fbpx
Wikipedia

Pregnancy

March 20, 2023

This article is about pregnancy in humans. For other mammals, see Pregnancy (mammals). For fish, see Pregnancy in fish.
"Trimester (pregnancy)" redirects here. For other uses of 'trimester', see Trimester.

Pregnancy is the time during which one or more offspring develops (gestates) inside a woman's uterus (womb).[4][13] A multiple pregnancy involves more than one offspring, such as with twins.[14]

Pregnancy
Other namesGestation
A woman in the third trimester of pregnancy
SpecialtyObstetrics, midwifery
SymptomsMissed periods, tender breasts, nausea and vomiting, hunger, frequent urination[1]
ComplicationsMiscarriage, high blood pressure of pregnancy, gestational diabetes, iron-deficiency anemia, severe nausea and vomiting[2][3]
Duration~40 weeks from the last menstrual period (38 weeks after conception)[4][5]
CausesSexual intercourse, assisted reproductive technology[6]
Diagnostic methodPregnancy test[7]
PreventionBirth control (including emergency contraception)[8]
TreatmentPrenatal care,[9] abortion[8]
MedicationFolic acid, iron supplements[9][10]
Frequency213 million (2012)[11]
Deaths 230,600 (2016)[12]

Pregnancy usually occurs by sexual intercourse, but can also occur through assisted reproductive technology procedures.[6] A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age.[4][5] This is just over nine months. Counting by fertilization age, the length is about 38 weeks.[5][13] Pregnancy is "the presence of an implanted human embryo or fetus in the uterus"; implantation occurs on average 8–9 days after fertilization.[15] An embryo is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term fetus is used until birth.[5]

Signs and symptoms of early pregnancy may include missed periods, tender breasts, morning sickness (nausea and vomiting), hunger, implantation bleeding, and frequent urination.[1] Pregnancy may be confirmed with a pregnancy test.[7] Methods of birth control—or, more accurately, contraception—are used to avoid pregnancy.

Pregnancy is divided into three trimesters of approximately three months each. The first trimester includes conception, which is when the sperm fertilizes the egg. The fertilized egg then travels down the Fallopian tube and attaches to the inside of the uterus, where it begins to form the embryo and placenta. During the first trimester, the possibility of miscarriage (natural death of embryo or fetus) is at its highest. Around the middle of the second trimester, movement of the fetus may be felt. At 28 weeks, more than 90% of babies can survive outside of the uterus if provided with high-quality medical care, though babies born at this time will likely experience serious health complications such as heart and respiratory problems and long-term intellectual and developmental disabilities.

Prenatal care improves pregnancy outcomes.[9] Nutrition during pregnancy is important to ensure healthy growth of the fetus.[16] Prenatal care may also include avoiding recreational drugs (including tobacco and alcohol), taking regular exercise, having blood tests, and regular physical examinations.[9] Complications of pregnancy may include disorders of high blood pressure, gestational diabetes, iron-deficiency anemia, and severe nausea and vomiting.[3] In the ideal childbirth, labor begins on its own "at term".[17] Babies born before 37 weeks are "preterm" and at higher risk of health problems such as cerebral palsy.[4] Babies born between weeks 37 and 39 are considered "early term" while those born between weeks 39 and 41 are considered "full term".[4] Babies born between weeks 41 and 42 weeks are considered "late term" while after 42 weeks they are considered "post term".[4] Delivery before 39 weeks by labor induction or caesarean section is not recommended unless required for other medical reasons.[18]

About 213 million pregnancies occurred in 2012, of which, 190 million (89%) were in the developing world and 23 million (11%) were in the developed world.[11] The number of pregnancies in women aged between 15 and 44 is 133 per 1,000 women.[11] About 10% to 15% of recognized pregnancies end in miscarriage.[2] In 2016, complications of pregnancy resulted in 230,600 maternal deaths, down from 377,000 deaths in 1990.[12] Common causes include bleeding, infections, hypertensive diseases of pregnancy, obstructed labor, miscarriage, abortion, or ectopic pregnancy.[12] Globally, 44% of pregnancies are unplanned.[19] Over half (56%) of unplanned pregnancies are aborted.[19] Among unintended pregnancies in the United States, 60% of the women used birth control to some extent during the month pregnancy began.[20]

Terminology

 
William Hunter, Anatomia uteri humani gravidi tabulis illustrata, 1774

Associated terms for pregnancy are gravid and parous. Gravidus and gravid come from the Latin word meaning "heavy" and a pregnant female is sometimes referred to as a gravida.[21] Gravidity refers to the number of times that a female has been pregnant. Similarly, the term parity is used for the number of times that a female carries a pregnancy to a viable stage.[22] Twins and other multiple births are counted as one pregnancy and birth.

A woman who has never been pregnant is referred to as a nulligravida. A woman who is (or has been only) pregnant for the first time is referred to as a primigravida,[23] and a woman in subsequent pregnancies as a multigravida or as multiparous.[21][24] Therefore, during a second pregnancy a woman would be described as gravida 2, para 1 and upon live delivery as gravida 2, para 2. In-progress pregnancies, abortions, miscarriages and/or stillbirths account for parity values being less than the gravida number. Women who have never carried a pregnancy more than 20 weeks are referred to as nulliparous.[25]

A pregnancy is considered term at 37 weeks of gestation. It is preterm if less than 37 weeks and postterm at or beyond 42 weeks of gestation. American College of Obstetricians and Gynecologists have recommended further division with early term 37 weeks up to 39 weeks, full term 39 weeks up to 41 weeks, and late term 41 weeks up to 42 weeks.[26] The terms preterm and postterm have largely replaced earlier terms of premature and postmature. Preterm and postterm are defined above, whereas premature and postmature have historical meaning and relate more to the infant's size and state of development rather than to the stage of pregnancy.[27][28]

Signs and symptoms

Main article: Signs and symptoms of pregnancy
Further information: Complications of pregnancy
 
Melasma: pigment changes to the face due to pregnancy
 
In the later part of pregnancy the uterus takes up much of the abdomen.

The usual signs and symptoms of pregnancy do not significantly interfere with activities of daily living or pose a health-threat to the mother or baby. However, pregnancy complications can cause other more severe symptoms, such as those associated with anemia.

Common signs and symptoms of pregnancy include:

Timeline

Comparison of dating systems for a typical pregnancy
Event Gestational age

(from the start of the last menstrual period)

Fertilization age Implantation age
Menstrual period begins Day 1 of pregnancy Not pregnant Not pregnant
Has sex and ovulates 2 weeks pregnant Not pregnant Not pregnant
Fertilization; cleavage stage begins[32] Day 15[32] Day 1[32][33] Not pregnant
Implantation of blastocyst begins Day 20 Day 6[32][33] Day 0
Implantation finished Day 26 Day 12[32][33] Day 6 (or Day 0)
Embryo stage begins; also, first missed period 4 weeks Day 15[32] Day 9
Primitive heart function can be detected 5 weeks, 5 days[32] Day 26[32] Day 20
Fetal stage begins 10 weeks, 1 day[32] 8 weeks, 1 day[32] 7 weeks, 2 days
First trimester ends 13 weeks 11 weeks 10 weeks
Second trimester ends 26 weeks 24 weeks 23 weeks
Childbirth 39–40 weeks 37–38 weeks[33]: 108  36–37 weeks

The chronology of pregnancy is, unless otherwise specified, generally given as gestational age, where the starting point is the beginning of the woman's last menstrual period (LMP), or the corresponding age of the gestation as estimated by a more accurate method if available. This model means that the woman is counted as being "pregnant" two weeks before conception and three weeks before implantation. Sometimes, timing may also use the fertilization age, which is the age of the embryo since conception.

Start of gestational age

Main article: Gestational age

The American Congress of Obstetricians and Gynecologists recommend the following methods to calculate gestational age:[34]

  • Directly calculating the days since the beginning of the last menstrual period.
  • Early obstetric ultrasound, comparing the size of an embryo or fetus to that of a reference group of pregnancies of known gestational age (such as calculated from last menstrual periods), and using the mean gestational age of other embryos or fetuses of the same size. If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period, it is still the one from the early ultrasound that is used for the rest of the pregnancy.[34]
  • In case of in vitro fertilization, calculating days since oocyte retrieval or co-incubation and adding 14 days.[35]

Trimesters

Pregnancy is divided into three trimesters, each lasting for approximately three months.[4] The exact length of each trimester can vary between sources. A typical pregnancy lasts about a year.

  • The first trimester begins with the start of gestational age as described above, that is, the beginning of week 1, or 0 weeks + 0 days of gestational age (GA). It ends at week 12 (11 weeks + 6 days of GA)[4] or end of week 14 (13 weeks + 6 days of GA).[36]
  • The second trimester is defined as starting, between the beginning of week 13 (12 weeks +0 days of GA)[4] and beginning of week 15 (14 weeks + 0 days of GA).[36] It ends at the end of week 27 (26 weeks + 6 days of GA)[36] or end of week 28 (27 weeks + 6 days of GA).[4]
  • The third trimester is defined as starting, between the beginning of week 28 (27 weeks + 0 days of GA)[36] or beginning of week 29 (28 weeks + 0 days of GA).[4] It lasts until childbirth.
 
Timeline of pregnancy, including (from top to bottom): Trimesters, embryo/fetus development, gestational age in weeks and months, viability and maturity stages

Estimation of due date

 
Distribution of gestational age at childbirth among singleton live births, given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period.[37] Roughly 80% of births occur between 37 and 41 weeks of gestational age.
Main article: Estimated date of delivery

Due date estimation basically follows two steps:

  • Determination of which time point is to be used as origin for gestational age, as described in the section above.
  • Adding the estimated gestational age at childbirth to the above time point. Childbirth on average occurs at a gestational age of 280 days (40 weeks), which is therefore often used as a standard estimation for individual pregnancies.[38] However, alternative durations as well as more individualized methods have also been suggested.

The American College of Obstetricians and Gynecologists divides full term into three divisions:[39]

  • Early-term: 37 weeks and 0 days through 38 weeks and 6 days
  • Full-term: 39 weeks and 0 days through 40 weeks and 6 days
  • Late-term: 41 weeks and 0 days through 41 weeks and 6 days
  • Post-term: greater than or equal to 42 weeks and 0 days

Naegele's rule is a standard way of calculating the due date for a pregnancy when assuming a gestational age of 280 days at childbirth. The rule estimates the expected date of delivery (EDD) by adding a year, subtracting three months, and adding seven days to the origin of gestational age. Alternatively there are mobile apps, which essentially always give consistent estimations compared to each other and correct for leap year, while pregnancy wheels made of paper can differ from each other by 7 days and generally do not correct for leap year.[40]

Furthermore, actual childbirth has only a certain probability of occurring within the limits of the estimated due date. A study of singleton live births came to the result that childbirth has a standard deviation of 14 days when gestational age is estimated by first trimester ultrasound, and 16 days when estimated directly by last menstrual period.[37]

Physiology

Capacity

Further information: Pregnancy over age 50

Fertility and fecundity are the respective capacities to fertilize and establish a clinical pregnancy and have a live birth. Infertility is an impaired ability to establish a clinical pregnancy and sterility is the permanent inability to establish a clinical pregnancy.[41]

The capacity for pregnancy depends on the reproductive system, its development and its variation, as well as on the condition of a person. Women as well as intersex and transgender people who have a functioning female reproductive system are capable of pregnancy. In some cases, someone might be able to produce fertilizable eggs, but might not have a womb or none that can sufficiently gestate, in which case they might find surrogacy.[42]

Initiation

See also: Human fertilization
 
Fertilization and implantation in humans.

Through an interplay of hormones that includes follicle stimulating hormone that stimulates folliculogenesis and oogenesis creates a mature egg cell, the female gamete. Fertilization is the event where the egg cell fuses with the male gamete, spermatozoon. After the point of fertilization, the fused product of the female and male gamete is referred to as a zygote or fertilized egg. The fusion of female and male gametes usually occurs following the act of sexual intercourse. Pregnancy rates for sexual intercourse are highest during the menstrual cycle time from some 5 days before until 1 to 2 days after ovulation.[43] Fertilization can also occur by assisted reproductive technology such as artificial insemination and in vitro fertilisation.

Fertilization (conception) is sometimes used as the initiation of pregnancy, with the derived age being termed fertilization age. Fertilization usually occurs about two weeks before the next expected menstrual period.

A third point in time is also considered by some people to be the true beginning of a pregnancy: This is time of implantation, when the future fetus attaches to the lining of the uterus. This is about a week to ten days after fertilization.[44]

Development of embryo and fetus

Main articles: Human embryonic development, Prenatal development, and Fetus
 
The initial stages of human embryogenesis

The sperm and the egg cell, which has been released from one of the female's two ovaries, unite in one of the two Fallopian tubes. The fertilized egg, known as a zygote, then moves toward the uterus, a journey that can take up to a week to complete. Cell division begins approximately 24 to 36 hours after the female and male cells unite. Cell division continues at a rapid rate and the cells then develop into what is known as a blastocyst. The blastocyst arrives at the uterus and attaches to the uterine wall, a process known as implantation.

The development of the mass of cells that will become the infant is called embryogenesis during the first approximately ten weeks of gestation. During this time, cells begin to differentiate into the various body systems. The basic outlines of the organ, body, and nervous systems are established. By the end of the embryonic stage, the beginnings of features such as fingers, eyes, mouth, and ears become visible. Also during this time, there is development of structures important to the support of the embryo, including the placenta and umbilical cord. The placenta connects the developing embryo to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. The umbilical cord is the connecting cord from the embryo or fetus to the placenta.

After about ten weeks of gestational age—which is the same as eight weeks after conception—the embryo becomes known as a fetus.[45] At the beginning of the fetal stage, the risk of miscarriage decreases sharply.[46] At this stage, a fetus is about 30 mm (1.2 inches) in length, the heartbeat is seen via ultrasound, and the fetus makes involuntary motions.[47] During continued fetal development, the early body systems, and structures that were established in the embryonic stage continue to develop. Sex organs begin to appear during the third month of gestation. The fetus continues to grow in both weight and length, although the majority of the physical growth occurs in the last weeks of pregnancy.

Electrical brain activity is first detected at the end of week 5 of gestation, but as in brain-dead patients, it is primitive neural activity rather than the beginning of conscious brain activity. Synapses do not begin to form until week 17.[48] Neural connections between the sensory cortex and thalamus develop as early as 24 weeks' gestational age, but the first evidence of their function does not occur until around 30 weeks, when minimal consciousness, dreaming, and the ability to feel pain emerges.[49]

Although the fetus begins to move during the first trimester, it is not until the second trimester that movement, known as quickening, can be felt. This typically happens in the fourth month, more specifically in the 20th to 21st week, or by the 19th week if the woman has been pregnant before. It is common for some women not to feel the fetus move until much later. During the second trimester, when the body size changes, maternity clothes may be worn.

  •  

    Embryo at 4 weeks after fertilization (gestational age of 6 weeks)

  •  

    Fetus at 8 weeks after fertilization (gestational age of 10 weeks)

  •  

    Fetus at 18 weeks after fertilization (gestational age of 20 weeks)

  •  

    Fetus at 38 weeks after fertilization (gestational age of 40 weeks)

  •  

    Relative size in 1st month (simplified illustration)

  •  

    Relative size in 3rd month (simplified illustration)

  •  

    Relative size in 5th month (simplified illustration)

  •  

    Relative size in 9th month (simplified illustration)

Maternal changes

 
The uterus expands making up a larger and larger portion of the abdomen. During the final stages of gestation the uterus may drop to a lower position.
Main article: Maternal physiological changes in pregnancy
 
Breast changes as seen during pregnancy. The areolae are larger and darker.

During pregnancy, a woman undergoes many physiological changes, which are entirely normal, including behavioral, cardiovascular, hematologic, metabolic, renal, and respiratory changes. Increases in blood sugar, breathing, and cardiac output are all required. Levels of progesterone and estrogens rise continually throughout pregnancy, suppressing the hypothalamic axis and therefore also the menstrual cycle. A full-term pregnancy at an early age (< 25) reduces the risk of breast, ovarian and endometrial cancer and the risk declines further with each additional full-term pregnancy.[50][51]

 
End of second trimester + 2 weeks (26 weeks of pregnancy)

The fetus is genetically different from its mother, and can be viewed as an unusually successful allograft.[52] The main reason for this success is increased immune tolerance during pregnancy.[53] Immune tolerance is the concept that the body is able to not mount an immune system response against certain triggers.[52]

During the first trimester, minute ventilation increases by 40%.[54] The womb will grow to the size of a lemon by eight weeks. Many symptoms and discomforts of pregnancy like nausea and tender breasts appear in the first trimester.[55]

During the second trimester, most women feel more energized, and begin to put on weight as the symptoms of morning sickness subside and eventually fade away. The uterus, the muscular organ that holds the developing fetus, can expand up to 20 times its normal size during pregnancy.

Braxton Hicks contractions are sporadic uterine contractions that may start around six weeks into a pregnancy; however, they are usually not felt until the second or third trimester.[56]

Final weight gain takes place during the third trimester, which is the most weight gain throughout the pregnancy. The woman's abdomen will transform in shape as it drops due to the fetus turning in a downward position ready for birth. During the second trimester, the woman's abdomen would have been upright, whereas in the third trimester it will drop down low. The fetus moves regularly, and is felt by the woman. Fetal movement can become strong and be disruptive to the woman. The woman's navel will sometimes become convex, "popping" out, due to the expanding abdomen.

 
Third trimester pregnant woman

Head engagement, also called "lightening" or "dropping", occurs as the fetal head descends into a cephalic presentation. While it relieves pressure on the upper abdomen and gives a renewed ease in breathing, it also severely reduces bladder capacity resulting in a need to void more frequently, and increases pressure on the pelvic floor and the rectum. It is not possible to predict when lightening occurs. In a first pregnancy it may happen a few weeks before the due date, though it may happen later or even not until labor begins, as is typical with subsequent pregnancies.[57]

It is also during the third trimester that maternal activity and sleep positions may affect fetal development due to restricted blood flow. For instance, the enlarged uterus may impede blood flow by compressing the vena cava when lying flat, which is relieved by lying on the left side.[58]

Childbirth

Main article: Childbirth

Childbirth, referred to as labor and delivery in the medical field, is the process whereby an infant is born.[59]

A woman is considered to be in labour when she begins experiencing regular uterine contractions, accompanied by changes of her cervix—primarily effacement and dilation. While childbirth is widely experienced as painful, some women do report painless labours, while others find that concentrating on the birth helps to quicken labour and lessen the sensations. Most births are successful vaginal births, but sometimes complications arise and a woman may undergo a cesarean section.

During the time immediately after birth, both the mother and the baby are hormonally cued to bond, the mother through the release of oxytocin, a hormone also released during breastfeeding. Studies show that skin-to-skin contact between a mother and her newborn immediately after birth is beneficial for both the mother and baby. A review done by the World Health Organization found that skin-to-skin contact between mothers and babies after birth reduces crying, improves mother–infant interaction, and helps mothers to breastfeed successfully. They recommend that neonates be allowed to bond with the mother during their first two hours after birth, the period that they tend to be more alert than in the following hours of early life.[60]

Childbirth maturity stages

Further information: Preterm birth and Postterm pregnancy

Stages of pregnancy term
stage starts ends
Preterm[61] - at 37 weeks
Early term[62] 37 weeks 39 weeks
Full term[62] 39 weeks 41 weeks
Late term[62] 41 weeks 42 weeks
Postterm[62] 42 weeks -

In the ideal childbirth labor begins on its own when a woman is "at term".[17] Events before completion of 37 weeks are considered preterm.[61] Preterm birth is associated with a range of complications and should be avoided if possible.[63]

Sometimes if a woman's water breaks or she has contractions before 39 weeks, birth is unavoidable.[62] However, spontaneous birth after 37 weeks is considered term and is not associated with the same risks of a preterm birth.[59] Planned birth before 39 weeks by caesarean section or labor induction, although "at term", results in an increased risk of complications.[64] This is from factors including underdeveloped lungs of newborns, infection due to underdeveloped immune system, feeding problems due to underdeveloped brain, and jaundice from underdeveloped liver.[65]

Babies born between 39 and 41 weeks' gestation have better outcomes than babies born either before or after this range.[62] This special time period is called "full term".[62] Whenever possible, waiting for labor to begin on its own in this time period is best for the health of the mother and baby.[17] The decision to perform an induction must be made after weighing the risks and benefits, but is safer after 39 weeks.[17]

Events after 42 weeks are considered postterm.[62] When a pregnancy exceeds 42 weeks, the risk of complications for both the woman and the fetus increases significantly.[66][67] Therefore, in an otherwise uncomplicated pregnancy, obstetricians usually prefer to induce labour at some stage between 41 and 42 weeks.[68]

Postnatal period

Main article: Postpartum period

The postpartum period also referred to as the puerperium, is the postnatal period that begins immediately after delivery and extends for about six weeks.[59] During this period, the mother's body begins the return to pre-pregnancy conditions that includes changes in hormone levels and uterus size.[59]

Diagnosis

The beginning of pregnancy may be detected either based on symptoms by the woman herself, or by using pregnancy tests. However, an important condition with serious health implications that is quite common is the denial of pregnancy by the pregnant woman. About 1 in 475 denials will last until around the 20th week of pregnancy. The proportion of cases of denial, persisting until delivery is about 1 in 2500.[69] Conversely, some non-pregnant women have a very strong belief that they are pregnant along with some of the physical changes. This condition is known as a false pregnancy.[70]

Physical signs

Further information: Symptoms and discomforts of pregnancy
 
Linea nigra in a woman at 22 weeks pregnant

Most pregnant women experience a number of symptoms,[71] which can signify pregnancy. A number of early medical signs are associated with pregnancy.[72][73] These signs include:

Biomarkers

Further information: Pregnancy test

Pregnancy detection can be accomplished using one or more various pregnancy tests,[75] which detect hormones generated by the newly formed placenta, serving as biomarkers of pregnancy.[76] Blood and urine tests can detect pregnancy 12 days after implantation.[77] Blood pregnancy tests are more sensitive than urine tests (giving fewer false negatives).[78] Home pregnancy tests are urine tests, and normally detect a pregnancy 12 to 15 days after fertilization.[79] A quantitative blood test can determine approximately the date the embryo was conceived because hCG doubles every 36 to 48 hours.[59] A single test of progesterone levels can also help determine how likely a fetus will survive in those with a threatened miscarriage (bleeding in early pregnancy).[80]

Ultrasound

Main article: Obstetric ultrasonography

Obstetric ultrasonography can detect fetal abnormalities, detect multiple pregnancies, and improve gestational dating at 24 weeks.[81] The resultant estimated gestational age and due date of the fetus are slightly more accurate than methods based on last menstrual period.[82] Ultrasound is used to measure the nuchal fold in order to screen for Down syndrome.[83]

Management

 
Flowchart showing the recommended weight limits for lifting at work during pregnancy as a function of lifting frequency, weeks of gestation, and the position of the lifted object relative to the lifter's body.[84][85]

Prenatal care

Main articles: Prenatal care and pre-conception counseling

Pre-conception counseling is care that is provided to a woman or couple to discuss conception, pregnancy, current health issues and recommendations for the period before pregnancy.[86]

Prenatal medical care is the medical and nursing care recommended for women during pregnancy, time intervals and exact goals of each visit differ by country.[87] Women who are high risk have better outcomes if they are seen regularly and frequently by a medical professional than women who are low risk.[88] A woman can be labeled as high risk for different reasons including previous complications in pregnancy, complications in the current pregnancy, current medical diseases, or social issues.[89][90]

The aim of good prenatal care is prevention, early identification, and treatment of any medical complications.[91] A basic prenatal visit consists of measurement of blood pressure, fundal height, weight and fetal heart rate, checking for symptoms of labor, and guidance for what to expect next.[86]

Nutrition

Main article: Nutrition and pregnancy

Nutrition during pregnancy is important to ensure healthy growth of the fetus.[16] Nutrition during pregnancy is different from the non-pregnant state.[16] There are increased energy requirements and specific micronutrient requirements.[16] Women benefit from education to encourage a balanced energy and protein intake during pregnancy.[92] Some women may need professional medical advice if their diet is affected by medical conditions, food allergies, or specific religious/ ethical beliefs.[93] Further studies are needed to access the effect of dietary advice to prevent gestational diabetes, although low quality evidence suggests some benefit.[94] Adequate periconceptional (time before and right after conception) folic acid (also called folate or Vitamin B9) intake has been shown to decrease the risk of fetal neural tube defects, such as spina bifida.[95] The neural tube develops during the first 28 days of pregnancy, a urine pregnancy test is not usually positive until 14 days post-conception, explaining the necessity to guarantee adequate folate intake before conception.[79][96] Folate is abundant in green leafy vegetables, legumes, and citrus.[97] In the United States and Canada, most wheat products (flour, noodles) are fortified with folic acid.[98]

Weight gain

The amount of healthy weight gain during a pregnancy varies.[99] Weight gain is related to the weight of the baby, the placenta, extra circulatory fluid, larger tissues, and fat and protein stores.[16] Most needed weight gain occurs later in pregnancy.[100]

The Institute of Medicine recommends an overall pregnancy weight gain for those of normal weight (body mass index of 18.5–24.9), of 11.3–15.9 kg (25–35 pounds) having a singleton pregnancy.[101] Women who are underweight (BMI of less than 18.5), should gain between 12.7 and 18 kg (28–40 lb), while those who are overweight (BMI of 25–29.9) are advised to gain between 6.8 and 11.3 kg (15–25 lb) and those who are obese (BMI ≥ 30) should gain between 5–9 kg (11–20 lb).[102] These values reference the expectations for a term pregnancy.

During pregnancy, insufficient or excessive weight gain can compromise the health of the mother and fetus.[100] The most effective intervention for weight gain in underweight women is not clear.[100] Being or becoming overweight in pregnancy increases the risk of complications for mother and fetus, including cesarean section, gestational hypertension, pre-eclampsia, macrosomia and shoulder dystocia.[99] Excessive weight gain can make losing weight after the pregnancy difficult.[99][103] Some of these complications are risk factors for stroke.[104]

Around 50% of women of childbearing age in developed countries like the United Kingdom are overweight or obese before pregnancy.[103] Diet modification is the most effective way to reduce weight gain and associated risks in pregnancy.[103]

Medication

Main article: Pharmaceutical drugs in pregnancy

Drugs used during pregnancy can have temporary or permanent effects on the fetus.[105] Anything (including drugs) that can cause permanent deformities in the fetus are labeled as teratogens.[106] In the U.S., drugs were classified into categories A, B, C, D and X based on the Food and Drug Administration (FDA) rating system to provide therapeutic guidance based on potential benefits and fetal risks.[107] Drugs, including some multivitamins, that have demonstrated no fetal risks after controlled studies in humans are classified as Category A.[105] On the other hand, drugs like thalidomide with proven fetal risks that outweigh all benefits are classified as Category X.[105]

Recreational drugs

See also: Neonatal withdrawal

The use of recreational drugs in pregnancy can cause various pregnancy complications.[59]

Exposure to toxins

Further information: Environmental toxicants and fetal development
A video describing research on N95 respirator use during advanced pregnancy

Intrauterine exposure to environmental toxins in pregnancy has the potential to cause adverse effects on prenatal development, and to cause pregnancy complications.[59] Air pollution has been associated with low birth weight infants.[114] Conditions of particular severity in pregnancy include mercury poisoning and lead poisoning.[59] To minimize exposure to environmental toxins, the American College of Nurse-Midwives recommends: checking whether the home has lead paint, washing all fresh fruits and vegetables thoroughly and buying organic produce, and avoiding cleaning products labeled "toxic" or any product with a warning on the label.[115]

Pregnant women can also be exposed to toxins in the workplace, including airborne particles. The effects of wearing an N95 filtering facepiece respirator are similar for pregnant women as for non-pregnant women, and wearing a respirator for one hour does not affect the fetal heart rate.[116]

Death by violence

Pregnant women or those who have recently given birth in the U.S. are more likely to be murdered than to die from obstetric causes. These homicides are a combination of intimate partner violence and firearms. Health authorities have called the violence "a health emergency for pregnant women," but say that pregnancy-related homicides are preventable if healthcare providers identify those women at risk and offer assistance to them.[117][118][119]

Sexual activity

Main article: Sexual activity during pregnancy

Most women can continue to engage in sexual activity, including sexual intercourse, throughout pregnancy.[120] Research suggests that during pregnancy both sexual desire and frequency of sexual relations decrease during the first and third trimester, with a rise during the second trimester.[121][122] I[123][124] Sex during pregnancy is a low-risk behavior except when the healthcare provider advises that sexual intercourse be avoided for particular medical reasons.[120] For a healthy pregnant woman, there is no single safe or right way to have sex during pregnancy.[120]

Exercise

Regular aerobic exercise during pregnancy appears to improve (or maintain) physical fitness.[125] Physical exercise during pregnancy appears to decrease the need for C-section,[126] and even vigorous exercise carries no significant risks to babies[127] and provides significant health benefits to the mother.[128] Bed rest, outside of research studies, is not recommended as there is no evidence of benefit and potential harm.[129]

The Clinical Practice Obstetrics Committee of Canada recommends that "All women without contraindications should be encouraged to participate in aerobic and strength-conditioning exercises as part of a healthy lifestyle during their pregnancy".[130] Although an upper level of safe exercise intensity has not been established, women who were regular exercisers before pregnancy and who have uncomplicated pregnancies should be able to engage in high intensity exercise programs, without a higher risk of prematurity, lower birth weight, or gestational weight gain.[127] In general, participation in a wide range of recreational activities appears to be safe, with the avoidance of those with a high risk of falling such as horseback riding or skiing or those that carry a risk of abdominal trauma, such as soccer or hockey.[131]

The American College of Obstetricians and Gynecologists reports that in the past, the main concerns of exercise in pregnancy were focused on the fetus and any potential maternal benefit was thought to be offset by potential risks to the fetus. However, they write that more recent information suggests that in the uncomplicated pregnancy, fetal injuries are highly unlikely.[131] They do, however, list several circumstances when a woman should contact her healthcare provider before continuing with an exercise program: vaginal bleeding, dyspnea before exertion, dizziness, headache, chest pain, muscle weakness, preterm labor, decreased fetal movement, amniotic fluid leakage, and calf pain or swelling (to rule out thrombophlebitis).[131]

Sleep

It has been suggested that shift work and exposure to bright light at night should be avoided at least during the last trimester of pregnancy to decrease the risk of psychological and behavioral problems in the newborn.[132]

Dental care

See also: Prenatal dental care

The increased levels of progesterone and estrogen during pregnancy make gingivitis more likely; the gums become edematous, red in colour, and tend to bleed.[133] Also a pyogenic granuloma or "pregnancy tumor", is commonly seen on the labial surface of the papilla. Lesions can be treated by local debridement or deep incision depending on their size, and by following adequate oral hygiene measures.[134] There have been suggestions that severe periodontitis may increase the risk of having preterm birth and low birth weight; however, a Cochrane review found insufficient evidence to determine if periodontitis can develop adverse birth outcomes.[135]

Flying

In low risk pregnancies, most health care providers approve flying until about 36 weeks of gestational age.[136] Most airlines allow pregnant women to fly short distances at less than 36 weeks, and long distances at less than 32 weeks.[137] Many airlines require a doctor's note that approves flying, especially at over 28 weeks.[137] During flights, the risk of deep vein thrombosis is decreased by getting up and walking occasionally, as well as by avoiding dehydration.[137]Full body scanners do not use ionizing radiation, and are safe in pregnancy.[138]

Pregnancy classes and birth plan

Main article: Birthing classes and birth plans

To prepare for the birth of the baby, health care providers recommend that parents attend antenatal classes during the third trimester of pregnancy. Classes include information about the process of labor and birth and the various kinds of births, including both vaginal and caesarean delivery, the use of forceps, and other interventions that may be needed to safely deliver the infant. Types of pain relief, including relaxation techniques, are discussed. Partners or others who may plan to support a woman during her labor and delivery learn how to assist in the birth.

It is also suggested that a birth plan be written at this time. A birth plan is a written statement that outlines the desires of the mother during labor and delivery of the baby. Discussing the birth plan with the midwife or other care provider gives parents a chance to ask questions and learn more about the process of labour.[139]

In 1991 the WHO launched the Baby-Friendly Hospital Initiative, a global program that recognizes birthing centers and hospitals that offer optimal levels of care for giving birth. Facilities that have been certified as "Baby Friendly" accept visits from expecting parents to familiarize them with the facility and the staff.[140]

Complications

Main article: Complications of pregnancy

Each year, ill health as a result of pregnancy is experienced (sometimes permanently) by more than 20 million women around the world.[141] In 2016, complications of pregnancy resulted in 230,600 deaths down from 377,000 deaths in 1990.[12] Common causes include bleeding (72,000), infections (20,000), hypertensive diseases of pregnancy (32,000), obstructed labor (10,000), and pregnancy with abortive outcome (20,000), which includes miscarriage, abortion, and ectopic pregnancy.[12]

The following are some examples of pregnancy complications:

There is also an increased susceptibility and severity of certain infections in pregnancy.

Miscarriage and stillbirth

Main articles: Miscarriage and Stillbirth
See also: Miscarriage and grief

Miscarriage is the most common complication of early pregnancy. It is defined as the loss of an embryo or fetus before it is able to survive independently. The most common symptom of miscarriage is vaginal bleeding with or without pain. The miscarriage may be evidenced by a clot-like material passing through and out of the vagina.[146] About 80% of miscarriages occur in the first 12 weeks of pregnancy. The underlying cause in about half of cases involves chromosomal abnormalities.[147]

Stillbirth is defined as fetal death after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. Each year about 21,000 babies are stillborn in the U.S.[148] Sadness, anxiety, and guilt may occur after a miscarriage or a stillbirth. Emotional support may help with processing the loss.[149] Fathers may experience grief over the loss as well. A large study found that there is a need to increase the accessibility of support services available for fathers.[150]

Diseases in pregnancy

Further information: Pre-existing disease in pregnancy

A pregnant woman may have a pre-existing disease, which is not directly caused by the pregnancy, but may cause complications to develop that include a potential risk to the pregnancy; or a disease may develop during pregnancy.

Abortion

Main article: Abortion

An abortion is the termination of an embryo or fetus via medical method. It is usually done within the first trimester, sometimes in the second, and rarely in the third. Reasons for pregnancies being undesired are broad,[155] rape being the most legally accepted.[156]

Birth control and education

Main article: Birth control

Family planning, as well as the availability and use of contraception, along with increased comprehensive sex education, has enabled many to prevent pregnancies when they are not desired. Schemes and funding to support education and the means to prevent pregnancies when they are not intended have been instrumental and are part of the third of the Sustainable Development Goals (SDGs) advanced by the United Nations.[157]

Technologies and science

Further information: Obstetrics

Assisted reproductive technology

Main article: Assisted reproductive technology

Modern reproductive medicine offers many forms of assisted reproductive technology for couples who stay childless against their will, such as fertility medication, artificial insemination, in vitro fertilization and surrogacy.

Medical imaging

 
CT scanning (volume rendered in this case) confers a radiation dose to the developing fetus.
 
A pregnant woman undergoing an ultrasound. Ultrasound is used to check on the growth and development of the fetus.
Main article: Medical imaging in pregnancy

Medical imaging may be indicated in pregnancy because of pregnancy complications, disease, or routine prenatal care. Medical ultrasonography including obstetric ultrasonography, and magnetic resonance imaging (MRI) without contrast agents are not associated with any risk for the mother or the fetus, and are the imaging techniques of choice for pregnant women.[158] Projectional radiography, CT scan and nuclear medicine imaging result in some degree of ionizing radiation exposure, but in most cases the absorbed doses are not associated with harm to the baby.[158] At higher dosages, effects can include miscarriage, birth defects and intellectual disability.[158]

Epidemiology

See also: Pregnancy rate and Advanced maternal age

About 213 million pregnancies occurred in 2012 of which 190 million were in the developing world and 23 million were in the developed world.[11] This is about 133 pregnancies per 1,000 women aged 15 to 44.[11] About 10% to 15% of recognized pregnancies end in miscarriage.[2] Globally, 44% of pregnancies are unplanned. Over half (56%) of unplanned pregnancies are aborted. In countries where abortion is prohibited, or only carried out in circumstances where the mother's life is at risk, 48% of unplanned pregnancies are aborted illegally. Compared to the rate in countries where abortion is legal, at 69%.[19]

Of pregnancies in 2012, 120 million occurred in Asia, 54 million in Africa, 19 million in Europe, 18 million in Latin America and the Caribbean, 7 million in North America, and 1 million in Oceania.[11] Pregnancy rates are 140 per 1000 women of childbearing age in the developing world and 94 per 1000 in the developed world.[11]

The rate of pregnancy, as well as the ages at which it occurs, differ by country and region. It is influenced by a number of factors, such as cultural, social and religious norms; access to contraception; and rates of education. The total fertility rate (TFR) in 2013 was estimated to be highest in Niger (7.03 children/woman) and lowest in Singapore (0.79 children/woman).[159]

In Europe, the average childbearing age has been rising continuously for some time. In Western, Northern, and Southern Europe, first-time mothers are on average 26 to 29 years old, up from 23 to 25 years at the start of the 1970s. In a number of European countries (Spain), the mean age of women at first childbirth has crossed the 30-year threshold.

This process is not restricted to Europe. Asia, Japan and the United States are all seeing average age at first birth on the rise, and increasingly the process is spreading to countries in the developing world like China, Turkey and Iran. In the US, the average age of first childbirth was 25.4 in 2010.[160]

In the United States and United Kingdom, 40% of pregnancies are unplanned, and between a quarter and half of those unplanned pregnancies were unwanted pregnancies.[161][162]

In the US, a woman's educational attainment and her marital status are correlated with childbearing: the percentage of women unmarried at the time of first birth drops with increasing educational level. In other words: among uneducated women, a large fraction (~80%) have their first child while they are unmarried. By contrast, few women with a bachelor's degree or higher (~25%) have their first child while unmarried. However, this phenomenon also has a strong generational component: in 1996, about 50% of women without a university degree had their first child being unmarried while that number increased to ~85% in 2018. Similarly, in 1996, only 4% of women with a BA degree or similar had their first child being unmarried. In 2018, that fraction increased to ~25%.[163]

Legal and social aspects

Legal protection

Further information: Reproductive rights and Reproductive justice

Many countries have various legal regulations in place to protect pregnant women and their children. Many countries have laws against pregnancy discrimination.[164]

Maternity Protection Convention ensures that pregnant women are exempt from activities such as night shifts or carrying heavy stocks. Maternity leave typically provides paid leave from work during roughly the last trimester of pregnancy and for some time after birth. Notable extreme cases include Norway (8 months with full pay) and the United States (no paid leave at all except in some states).

In the United States, some actions that result in miscarriage or stillbirth, such as beating a pregnant woman, are considered crimes. One law that does so is the federal Unborn Victims of Violence Act. In 2014, the American state of Tennessee passed a law which allows prosecutors to charge a woman with criminal assault if she uses illegal drugs during her pregnancy and her fetus or newborn is harmed as a result.[165]

However, protections are not universal. In Singapore, the Employment of Foreign Manpower Act forbids current and former work permit holders from becoming pregnant or giving birth in Singapore without prior permission.[166][167] Violation of the Act is punishable by a fine of up to S$10,000 (US$7300) and deportation,[166][168] and until 2010, their employers would lose their $5,000 security bond.[169]

Teenage pregnancy

Main article: Teenage pregnancy

Teenage pregnancy is also known as adolescent pregnancy.[170] The WHO defines adolescence as the period between the ages of 10 and 19 years.[171] Adolescents face higher health risks than women who give birth at age 20 to 24 and their infants are at a higher risk for preterm birth, low birth weight, and other severe neonatal conditions. Their children continue to face greater challenges, both behavioral and physical, throughout their lives. Teenage pregnancies are also related to social issues, including social stigma, lower educational levels, and poverty.[172][173][170] Studies show that female adolescents are often in abusive relationships at the time of their conceiving.[174]

Nurse-Family Partnership (NFP) is a non-profit organization operating in the United States and the UK designed to serve the needs of low income young mothers who may have special needs in their first pregnancy. Each mother served is partnered with a registered nurse early in her pregnancy and receives ongoing nurse home visits that continue through her child's second birthday. NFP intervention has been associated with improvements in maternal health, child health, and economic security.[175][176]

Racial disparities

There are significant racial imbalances in pregnancy and neonatal care systems.[177] Midwifery guidance, treatment, and care have been related to better birth outcomes. Diminishing racial inequities in health is an increasingly large public health challenge in the United States. Despite the fact that average rates have decreased, data on neonatal mortality demonstrates that racial disparities have persisted and grown. The death rate for African American babies is nearly double that of white neonates. According to studies, congenital defects, SIDS, preterm birth, and low birth weight are all more common among African American babies.[178]

Midwifery care has been linked to better birth and postpartum outcomes for both mother and child. It caters to the needs of the woman and provides competent, sympathetic care, and is essential for maternal health improvement. The presence of a doula, or birth assistant, during labor and delivery, has also been associated with improved levels of satisfaction with medical birth care. Providers recognized their profession from a historical standpoint, a link to African origins, the diaspora, and prevailing African American struggles. Providers participated in both direct clinical experience and activist involvement. Advocacy efforts aimed to enhance the number of minority birth attendants and to promote the benefits of woman-centered birth care to neglected areas.[178]

Transgender people

Main article: Transgender pregnancy

Transgender people have experienced significant advances in societal acceptance in recent years leaving many health professionals unprepared to provide quality care. A 2015 report suggests that "numbers of transgender individuals who are seeking family planning, fertility, and pregnancy services could certainly be quite large". Regardless of prior hormone replacement therapy treatments, the progression of pregnancy and birthing procedures for transgender people who carry pregnancies are typically the same as those of cisgender women[179] however, they may be subjected to discrimination, which can include a variety of negative social, emotional, and medical experiences, as pregnancy is regarded as an exclusively female activity. According to a study by the American College of Obstetricians and Gynecologists, there is a lack of awareness, services, and medical assistance available to pregnant trans men.[180]

Culture

 
The Visitation: Mary, pregnant with Jesus, visiting pregnant Elizabeth, depicted as a statue at the Church of the Visitation in Ein Karem, Israel.

In most cultures, pregnant women have a special status in society and receive particularly gentle care.[181] At the same time, they are subject to expectations that may exert great psychological pressure, such as having to produce a son and heir. In many traditional societies, pregnancy must be preceded by marriage, on pain of ostracism of mother and (illegitimate) child.

Overall, pregnancy is accompanied by numerous customs that are often subject to ethnological research, often rooted in traditional medicine or religion. The baby shower is an example of a modern custom.

Pregnancy is an important topic in sociology of the family. The prospective child may preliminarily be placed into numerous social roles. The parents' relationship and the relation between parents and their surroundings are also affected.

A belly cast may be made during pregnancy as a keepsake.

Arts

Main article: Pregnancy in art

Images of pregnant women, especially small figurines, were made in traditional cultures in many places and periods, though it is rarely one of the most common types of image. These include ceramic figures from some Pre-Columbian cultures, and a few figures from most of the ancient Mediterranean cultures. Many of these seem to be connected with fertility. Identifying whether such figures are actually meant to show pregnancy is often a problem, as well as understanding their role in the culture concerned.

Among the oldest surviving examples of the depiction of pregnancy are prehistoric figurines found across much of Eurasia and collectively known as Venus figurines. Some of these appear to be pregnant.

Due to the important role of the Mother of God in Christianity, the Western visual arts have a long tradition of depictions of pregnancy, especially in the biblical scene of the Visitation, and devotional images called a Madonna del Parto.[182]

The unhappy scene usually called Diana and Callisto, showing the moment of discovery of Callisto's forbidden pregnancy, is sometimes painted from the Renaissance onwards. Gradually, portraits of pregnant women began to appear, with a particular fashion for "pregnancy portraits" in elite portraiture of the years around 1600.

Pregnancy, and especially pregnancy of unmarried women, is also an important motif in literature. Notable examples include Thomas Hardy's 1891 novel Tess of the d'Urbervilles and Goethe's 1808 play Faust.

See also

References

  1. ^ a b "What are some common signs of pregnancy?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 12 July 2013. from the original on 19 March 2015. Retrieved 14 March 2015.
  2. ^ a b c The Johns Hopkins Manual of Gynecology and Obstetrics (4 ed.). Lippincott Williams & Wilkins. 2012. p. 438. ISBN 978-1-4511-4801-5. from the original on 10 September 2017.
  3. ^ a b "What are some common complications of pregnancy?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 12 July 2013. from the original on 26 February 2015. Retrieved 14 March 2015.
  4. ^ a b c d e f g h i j k "Pregnancy: Condition Information". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 19 December 2013. from the original on 19 March 2015. Retrieved 14 March 2015.
  5. ^ a b c d Abman SH (2011). Fetal and neonatal physiology (4th ed.). Philadelphia: Elsevier/Saunders. pp. 46–47. ISBN 978-1-4160-3479-7.
  6. ^ a b Shehan CL (2016). The Wiley Blackwell Encyclopedia of Family Studies, 4 Volume Set. John Wiley & Sons. p. 406. ISBN 978-0-470-65845-1. from the original on 10 September 2017.
  7. ^ a b "How do I know if I'm pregnant?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 30 November 2012. from the original on 2 April 2015. Retrieved 14 March 2015.
  8. ^ a b Taylor D, James EA (2011). "An evidence-based guideline for unintended pregnancy prevention". Journal of Obstetric, Gynecologic, and Neonatal Nursing. 40 (6): 782–793. doi:10.1111/j.1552-6909.2011.01296.x. PMC 3266470. PMID 22092349.
  9. ^ a b c d "What is prenatal care and why is it important?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 12 July 2013. from the original on 2 April 2015. Retrieved 14 March 2015.
  10. ^ Keats EC, Haider BA, Tam E, Bhutta ZA (March 2019). "Multiple-micronutrient supplementation for women during pregnancy". The Cochrane Database of Systematic Reviews. 3 (3): CD004905. doi:10.1002/14651858.CD004905.pub6. PMC 6418471. PMID 30873598.
  11. ^ a b c d e f g Sedgh G, Singh S, Hussain R (September 2014). "Intended and unintended pregnancies worldwide in 2012 and recent trends". Studies in Family Planning. 45 (3): 301–314. doi:10.1111/j.1728-4465.2014.00393.x. PMC 4727534. PMID 25207494.
  12. ^ a b c d e Naghavi, Mohsen; et al. (GBD 2016 Causes of Death Collaborators) (September 2017). "Global, regional, and national age-sex specific mortality for 264 causes of death, 1980-2016: a systematic analysis for the Global Burden of Disease Study 2016". Lancet. 390 (10100): 1151–1210. doi:10.1016/S0140-6736(17)32152-9. PMC 5605883. PMID 28919116.
  13. ^ a b Mosby (2009). Mosby's Pocket Dictionary of Medicine, Nursing & Health Professions - E-Book. Elsevier Health Sciences. p. 1078. ISBN 978-0323066044.
  14. ^ Wylie L (2005). Essential anatomy and physiology in maternity care (Second ed.). Edinburgh: Churchill Livingstone. p. 172. ISBN 978-0-443-10041-3. from the original on 10 September 2017.
  15. ^ Massachusetts General Laws c.112 § 12K: Definitions applicable to Secs. 12L to 12U, Commonwealth of Massachusetts, 2022
  16. ^ a b c d e Lammi-Keefe CJ, Couch SC, Philipson EH, eds. (2008). Handbook of Nutrition and Pregnancy. Nutrition and health. Totowa, NJ: Humana Press. p. 28. doi:10.1007/978-1-59745-112-3. ISBN 978-1-59745-112-3.
  17. ^ a b c d American Congress of Obstetricians and Gynecologists (February 2013), "Five Things Physicians and Patients Should Question", Choosing Wisely: an initiative of the ABIM Foundation, American Congress of Obstetricians and Gynecologists, from the original on 1 September 2013, retrieved 1 August 2013
  18. ^ World Health Organization (November 2014). "Preterm birth Fact sheet N°363". who.int. from the original on 7 March 2015. Retrieved 6 March 2015.
  19. ^ a b c Bearak J, Popinchalk A, Alkema L, Sedgh G (April 2018). "Global, regional, and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014: estimates from a Bayesian hierarchical model". The Lancet. Global Health. 6 (4): e380–e389. doi:10.1016/S2214-109X(18)30029-9. PMC 6055480. PMID 29519649.
  20. ^ Hurt KJ, Guile MW, Bienstock JL, Fox HE, Wallach EE (28 March 2012). The Johns Hopkins manual of gynecology and obstetrics (4th ed.). Philadelphia: Wolters Kluwer Health / Lippincott Williams & Wilkins. p. 382. ISBN 978-1-60547-433-5.
  21. ^ a b "definition of gravida". The Free Dictionary. Retrieved 17 January 2008.
  22. ^ "Gravidity and Parity Definitions (Implications in Risk Assessment)". patient.info. from the original on 12 December 2016.
  23. ^ Robinson, Victor, ed. (1939). "Primipara". The Modern Home Physician, A New Encyclopedia of Medical Knowledge. WM. H. Wise & Company (New York)., page 596.
  24. ^ . Merriam-Webster, Incorporated. Archived from the original on 8 September 2008. Retrieved 9 March 2012.
  25. ^ "Nulliparous definition". MedicineNet, Inc. 18 November 2000. from the original on 9 July 2009.
  26. ^ "Definition of Term Pregnancy – ACOG". www.acog.org. Retrieved 27 September 2019.
  27. ^ "Definition of Premature birth". Medicine.net. from the original on 9 July 2009. Retrieved 16 January 2008.
  28. ^ Lama Rimawi, MD (22 September 2006). "Premature Infant". Disease & Conditions Encyclopedia. Discovery Communications, LLC. from the original on 19 January 2008. Retrieved 16 January 2008.
  29. ^ Merck. "Urinary tract infections during pregnancy". Merck Manual Home Health Handbook. from the original on 10 November 2011.
  30. ^ Vazquez JC (August 2010). "Constipation, haemorrhoids, and heartburn in pregnancy". BMJ Clinical Evidence. 2010: 1411. PMC 3217736. PMID 21418682.
  31. ^ MedlinePlus > Breast pain Archived 5 August 2012 at archive.today Update Date: 31 December 2008. Updated by: David C. Dugdale, Susan Storck. Also reviewed by David Zieve.
  32. ^ a b c d e f g h i j Nair M, Kumar B (7 April 2016). "Embryology for fetal medicine". In Kumar B, Alfirevic Z (eds.). Fetal Medicine. Cambridge University Press. pp. 54–59. ISBN 978-1-107-06434-8.
  33. ^ a b c d Mishra S, ed. (7 August 2019). Langman's Medical Embryology. Wolters kluwer india Pvt Ltd. p. 48. ISBN 978-93-88696-53-1.
  34. ^ a b Obstetric Data Definitions Issues and Rationale for Change – Gestational Age & Term 6 November 2013 at the Wayback Machine from Patient Safety and Quality Improvement at American Congress of Obstetricians and Gynecologists. Created November 2012.
  35. ^ Tunón K, Eik-Nes SH, Grøttum P, Von Düring V, Kahn JA (January 2000). "Gestational age in pregnancies conceived after in vitro fertilization: a comparison between age assessed from oocyte retrieval, crown-rump length and biparietal diameter". Ultrasound in Obstetrics & Gynecology. 15 (1): 41–46. doi:10.1046/j.1469-0705.2000.00004.x. PMID 10776011. S2CID 20029116.
  36. ^ a b c d "Pregnancy – the three trimesters". University of California San Francisco. Retrieved 30 November 2019.
  37. ^ a b Hoffman CS, Messer LC, Mendola P, Savitz DA, Herring AH, Hartmann KE (November 2008). "Comparison of gestational age at birth based on last menstrual period and ultrasound during the first trimester". Paediatric and Perinatal Epidemiology. 22 (6): 587–596. doi:10.1111/j.1365-3016.2008.00965.x. PMID 19000297.
  38. ^ . Healthline Networks, Inc. Archived from the original on 21 December 2009. Retrieved 13 January 2010.
  39. ^ "ement Health IT and Clinical Informatics reVITALize: Obstetrics Data Definitions reVITALize: Obstetrics Data Definitions". ACOG. Retrieved 27 November 2022.
  40. ^ Chambliss LR, Clark SL (February 2014). "Paper gestational age wheels are generally inaccurate". American Journal of Obstetrics and Gynecology. 210 (2): 145.e1–145.e4. doi:10.1016/j.ajog.2013.09.013. PMID 24036402.
  41. ^ Zegers-Hochschild F, Adamson GD, Dyer S, Racowsky C, de Mouzon J, Sokol R, et al. (September 2017). "The International Glossary on Infertility and Fertility Care, 2017". Fertility and Sterility. Elsevier BV. 108 (3): 393–406. doi:10.1016/j.fertnstert.2017.06.005. PMID 28760517. S2CID 3640374.
  42. ^ "Differences in sex development". nhs.uk. 18 November 2021. Retrieved 29 June 2022.
  43. ^ Weschler T (2002). Taking Charge of Your Fertility (Revised ed.). New York: HarperCollins. pp. 242, 374. ISBN 978-0-06-093764-5.
  44. ^ Berger KS (2011). The Developing Person Through the Life Span. Macmillan. p. 90. ISBN 978-1-4292-3205-0. from the original on 25 April 2016.
  45. ^ "Stages of Development of the Fetus – Women's Health Issues". MSD Manual Consumer Version. Retrieved 10 July 2020.
  46. ^
    • Lennart Nilsson, A Child is Born 91 (1990): at eight weeks, "the danger of a miscarriage ... diminishes sharply."
    • "Women's Health Information 30 April 2007 at the Wayback Machine", Hearthstone Communications Limited: "The risk of miscarriage decreases dramatically after the 8th week as the weeks go by." Retrieved 2007-04-22.
  47. ^ Kalverboer AF, Gramsbergen AA (1 January 2001). Handbook of Brain and Behaviour in Human Development. Springer. p. 1. ISBN 978-0-7923-6943-1. from the original on 19 September 2015.
  48. ^ Illes J, ed. (2008). Neuroethics: defining the issues in theory, practice, and policy (Repr. ed.). Oxford: Oxford University Press. p. 142. ISBN 978-0-19-856721-9. from the original on 19 September 2015.
  49. ^
    • Harley TA (2021). The Science of Consciousness: Waking, Sleeping and Dreaming. Cambridge, United Kingdom: Cambridge University Press. p. 245. ISBN 978-1-107-12528-5. Retrieved 3 May 2022.
    • Cleeremans A, Wilken P, Bayne T, eds. (2009). The Oxford Companion to Consciousness. New York, NY: Oxford University Press. p. 229. ISBN 978-0-19-856951-0. Retrieved 3 May 2022.
    • Thompson E, Moscovitch M, Zelazo PD, eds. (2007). The Cambridge Handbook of Consciousness. Cambridge, United Kingdom: Cambridge University Press. pp. 415–417. ISBN 9781139464062. Retrieved 3 May 2022.
  50. ^ "Abortion & Pregnancy Risks". Louisiana Department of Health. Retrieved 22 August 2019.
  51. ^ "Reproductive History and Cancer Risk". National Cancer Institute. 30 November 2016. Retrieved 23 August 2019.
  52. ^ a b Mor G, ed. (2006). Immunology of pregnancy. Medical intelligence unit. Georgetown, Tex. : New York: Landes Bioscience/Eurekah.com; Springer Science+Business Media. pp. 1–4. doi:10.1007/0-387-34944-8. ISBN 978-0-387-34944-2.
  53. ^ Williams Z (September 2012). "Inducing tolerance to pregnancy". The New England Journal of Medicine. 367 (12): 1159–1161. doi:10.1056/NEJMcibr1207279. PMC 3644969. PMID 22992082.
  54. ^ Campbell LA, Klocke RA (April 2001). "Implications for the pregnant patient". American Journal of Respiratory and Critical Care Medicine. 163 (5): 1051–1054. doi:10.1164/ajrccm.163.5.16353. PMID 11316633.
  55. ^ "Your baby at 0–8 weeks pregnancy – Pregnancy and baby guide – NHS Choices". nhs.uk. 20 December 2017. from the original on 20 November 2013.
  56. ^ Hennen L, Murray L, Scott J (2005). The BabyCenter Essential Guide to Pregnancy and Birth: Expert Advice and Real-World Wisdom from THE tip Top Pregnancy and Parenting Resource. Emmaus, Penn.: Rodale Books. ISBN 1-59486-211-7.
  57. ^ "Pregnancy: Dropping (Lightening)". University of Michigan. Retrieved 9 June 2021.
  58. ^ Stacey T, Thompson JM, Mitchell EA, Ekeroma AJ, Zuccollo JM, McCowan LM (June 2011). "Association between maternal sleep practices and risk of late stillbirth: a case-control study". BMJ. 342: d3403. doi:10.1136/bmj.d3403. PMC 3114953. PMID 21673002.
  59. ^ a b c d e f g h i j k Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS, eds. (2014). . William's Obstetrics. McGraw-Hill Education. ISBN 978-0-07-179893-8. Archived from the original on 31 December 2018. Retrieved 9 November 2015.
  60. ^ . apps.who.int. Archived from the original on 27 December 2011.
  61. ^ a b World Health Organization (November 2013). "Preterm birth". who.int. from the original on 7 September 2014. Retrieved 19 September 2014.
  62. ^ a b c d e f g h American Congress of Obstetricians and Gynecologists; Society for Maternal-Fetal Medicine (22 October 2013). . acog.org. Archived from the original on 15 September 2014. Retrieved 19 September 2014.
  63. ^ Saigal S, Doyle LW (January 2008). "An overview of mortality and sequelae of preterm birth from infancy to adulthood". Lancet. 371 (9608): 261–269. doi:10.1016/S0140-6736(08)60136-1. PMID 18207020. S2CID 17256481.
  64. ^ American Congress of Obstetricians and Gynecologists (February 2013), "Five Things Physicians and Patients Should Question", Choosing Wisely: an initiative of the ABIM Foundation, American Congress of Obstetricians and Gynecologists, from the original on 1 September 2013, retrieved 1 August 2013, which cites
    • Main E, Oshiro B, Chagolla B, Bingham D, Dang-Kilduff L, Kowalewski L, (PDF), March of Dimes; California Maternal Quality Care Collaborative; Maternal, Child and Adolescent Health Division; Center for Family Health; California Department of Public Health, archived from the original (PDF) on 10 November 2012, retrieved 1 August 2013
  65. ^ Michele Norris (18 July 2011). "Doctors To Pregnant Women: Wait at Least 39 Weeks". All Things Considered. from the original on 23 July 2011. Retrieved 20 August 2011.
  66. ^ Norwitz ER. "Postterm Pregnancy (Beyond the Basics)". UpToDate, Inc. from the original on 7 October 2012. Retrieved 24 August 2012.
  67. ^ The American College of Obstetricians and Gynecologists (April 2006). . Medem. Medem, Inc. Archived from the original on 29 April 2003. Retrieved 16 January 2008.
  68. ^ (PDF). Royal College of Obstetricians and Gynaecologists. 2001. Archived from the original (PDF) on 30 December 2006. Retrieved 18 January 2008.
  69. ^ Jenkins A, Millar S, Robins J (July 2011). "Denial of pregnancy: a literature review and discussion of ethical and legal issues". Journal of the Royal Society of Medicine. 104 (7): 286–291. doi:10.1258/jrsm.2011.100376. PMC 3128877. PMID 21725094.
  70. ^ Gabbe S (1 January 2012). Obstetrics: normal and problem pregnancies (6th ed.). Philadelphia: Elsevier/Saunders. p. 1184. ISBN 978-1-4377-1935-2.
  71. ^ "Pregnancy Symptoms". National Health Service (NHS). 11 March 2010. from the original on 28 February 2010. Retrieved 11 March 2010.
  72. ^ a b "Early symptoms of pregnancy: What happens right away". Mayo Clinic. 22 February 2007. from the original on 14 September 2007. Retrieved 22 August 2007.
  73. ^ a b "Pregnancy Symptoms – Early Signs of Pregnancy: American Pregnancy Association". from the original on 15 January 2008. Retrieved 16 January 2008.
  74. ^ "Pregnancy video". Channel 4. 2008. from the original on 23 January 2009. Retrieved 22 January 2009.
  75. ^ "NHS Pregnancy Planner". National Health Service (NHS). 19 March 2010. Retrieved 19 March 2010.
  76. ^ Cole LA, Butler SA, eds. (2015). (2nd ed.). Amsterdam: Elsevier. ISBN 978-0-12-800821-8. Archived from the original on 26 January 2021. Retrieved 10 November 2015.
  77. ^ Qasim SM, Callan C, Choe JK (October 1996). "The predictive value of an initial serum beta human chorionic gonadotropin level for pregnancy outcome following in vitro fertilization". Journal of Assisted Reproduction and Genetics. 13 (9): 705–708. doi:10.1007/BF02066422. PMID 8947817. S2CID 36218409.
  78. ^ "BestBets: Serum or Urine beta-hCG?". from the original on 31 December 2008.
  79. ^ a b Cole LA, Khanlian SA, Sutton JM, Davies S, Rayburn WF (January 2004). "Accuracy of home pregnancy tests at the time of missed menses". American Journal of Obstetrics and Gynecology. 190 (1): 100–105. doi:10.1016/j.ajog.2003.08.043. PMID 14749643.
  80. ^ Verhaegen J, Gallos ID, van Mello NM, Abdel-Aziz M, Takwoingi Y, Harb H, et al. (September 2012). "Accuracy of single progesterone test to predict early pregnancy outcome in women with pain or bleeding: meta-analysis of cohort studies". BMJ. 345: e6077. doi:10.1136/bmj.e6077. PMC 3460254. PMID 23045257.
  81. ^ Whitworth M, Bricker L, Mullan C (July 2015). "Ultrasound for fetal assessment in early pregnancy". The Cochrane Database of Systematic Reviews. 2015 (7): CD007058. doi:10.1002/14651858.CD007058.pub3. PMC 4084925. PMID 26171896.
  82. ^ Nguyen TH, Larsen T, Engholm G, Møller H (July 1999). "Evaluation of ultrasound-estimated date of delivery in 17,450 spontaneous singleton births: do we need to modify Naegele's rule?". Ultrasound in Obstetrics & Gynecology. 14 (1): 23–28. doi:10.1046/j.1469-0705.1999.14010023.x. PMID 10461334. S2CID 30749264.
  83. ^ Pyeritz RE (2014). Current Medical Diagnosis & Treatment 2015. McGraw-Hill.
  84. ^ Waters TR, MacDonald LA, Hudock SD, Goddard DE (February 2014). "Provisional recommended weight limits for manual lifting during pregnancy". Human Factors. 56 (1): 203–214. doi:10.1177/0018720813502223. PMC 4606868. PMID 24669554. from the original on 1 April 2017.
  85. ^ MacDonald LA, Waters TR, Napolitano PG, Goddard DE, Ryan MA, Nielsen P, Hudock SD (August 2013). "Clinical guidelines for occupational lifting in pregnancy: evidence summary and provisional recommendations". American Journal of Obstetrics and Gynecology. 209 (2): 80–88. doi:10.1016/j.ajog.2013.02.047. PMC 4552317. PMID 23467051.
  86. ^ a b Lyons P (2015). . Current clinical practice (2nd ed.). Cham, Switzerland: Humana Press. pp. 19–28. ISBN 978-3-319-20077-4. Archived from the original on 26 January 2021. Retrieved 11 November 2015.
  87. ^ . www.who.int. Archived from the original on 20 November 2015. Retrieved 10 November 2015.
  88. ^ Dowswell T, Carroli G, Duley L, Gates S, Gülmezoglu AM, Khan-Neelofur D, Piaggio G, et al. (American College of Obstetricians Gynecologists Committee on Health Care for Undeserved Women) (July 2015). "Alternative versus standard packages of antenatal care for low-risk pregnancy". The Cochrane Database of Systematic Reviews. 2015 (7): CD000934. doi:10.1002/14651858.cd000934.pub3. PMC 7061257. PMID 26184394.
  89. ^ American College of Obstetricians Gynecologists Committee on Health Care for Undeserved Women (August 2006). "ACOG Committee Opinion No. 343: psychosocial risk factors: perinatal screening and intervention". Obstetrics and Gynecology. 108 (2): 469–477. doi:10.1097/00006250-200608000-00046. PMID 16880322.
  90. ^ Hurt JK, ed. (2011). The Johns Hopkins manual of gynecology and obstetrics (4th ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. ISBN 978-1-4511-0913-9.
  91. ^ McCormick MC, Siegel JE, eds. (1999). . Cambridge, UK; New York: Cambridge University Press. ISBN 978-0-521-66196-6. Archived from the original on 6 November 2018. Retrieved 10 November 2015.
  92. ^ Ota E, Hori H, Mori R, Tobe-Gai R, Farrar D (June 2015). "Antenatal dietary education and supplementation to increase energy and protein intake". The Cochrane Database of Systematic Reviews. 2015 (6): CD000032. doi:10.1002/14651858.CD000032.pub3. PMID 26031211.
  93. ^ "| Choose MyPlate". Choose MyPlate. 29 April 2015. from the original on 17 November 2015. Retrieved 15 November 2015.
  94. ^ Tieu J, Shepherd E, Middleton P, Crowther CA (January 2017). "Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus". The Cochrane Database of Systematic Reviews. 1 (1): CD006674. doi:10.1002/14651858.CD006674.pub3. PMC 6464792. PMID 28046205.
  95. ^ Klusmann A, Heinrich B, Stöpler H, Gärtner J, Mayatepek E, Von Kries R (November 2005). "A decreasing rate of neural tube defects following the recommendations for periconceptional folic acid supplementation". Acta Paediatrica. 94 (11): 1538–1542. doi:10.1080/08035250500340396. PMID 16303691. S2CID 13506877.
  96. ^ Stevenson RE, Allen WP, Pai GS, Best R, Seaver LH, Dean J, Thompson S (October 2000). "Decline in prevalence of neural tube defects in a high-risk region of the United States". Pediatrics. 106 (4): 677–683. doi:10.1542/peds.106.4.677. PMID 11015508. S2CID 39696556.
  97. ^ "Folic acid in diet: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. from the original on 17 November 2015. Retrieved 15 November 2015.
  98. ^ Centers for Disease Control Prevention (CDC) (January 2008). "Use of supplements containing folic acid among women of childbearing age--United States, 2007". MMWR. Morbidity and Mortality Weekly Report. 57 (1): 5–8. PMID 18185493.
  99. ^ a b c Viswanathan M, Siega-Riz AM, Moos MK, et al. (May 2008). Outcomes of Maternal Weight Gain. Evidence Reports/Technology Assessments, No. 168. Agency for Healthcare Research and Quality. pp. 1–223. PMC 4781425. PMID 18620471. from the original on 28 May 2013. Retrieved 23 June 2013.
  100. ^ a b c Institute for Quality and Efficiency in Health Care. "Weight gain in pregnancy". Fact sheet. Institute for Quality and Efficiency in Health Care. from the original on 14 December 2013. Retrieved 23 June 2013.
  101. ^ . Institute of Medicine. Archived from the original on 10 August 2010. Retrieved 29 July 2010.
  102. ^ American College of Obstetricians Gynecologists (January 2013). "ACOG Committee opinion no. 548: weight gain during pregnancy". Obstetrics and Gynecology. 121 (1): 210–212. doi:10.1097/01.AOG.0000425668.87506.4c. PMID 23262962.
  103. ^ a b c Thangaratinam S, Rogozińska E, Jolly K, Glinkowski S, Duda W, Borowiack E, et al. (July 2012). "Interventions to reduce or prevent obesity in pregnant women: a systematic review". Health Technology Assessment. National Institute for Health and Care Research. 16 (31): iii–iv, 1–191. doi:10.3310/hta16310. PMC 4781281. PMID 22814301.
  104. ^ Bushnell C, McCullough LD, Awad IA, Chireau MV, Fedder WN, Furie KL, et al. (May 2014). "Guidelines for the prevention of stroke in women: a statement for healthcare professionals from the American Heart Association/American Stroke Association". Stroke. 45 (5): 1545–1588. doi:10.1161/01.str.0000442009.06663.48. PMID 24503673. S2CID 6297484.
  105. ^ a b c Briggs GG, Freeman RK (2015). (Tenth ed.). Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins Health. p. Appendix. ISBN 978-1-4511-9082-3. Archived from the original on 25 February 2021. Retrieved 16 November 2015.
  106. ^ Genetic Alliance; The New England Public Health Genetics Education Collaborative (17 February 2010). "Appendix A: Teratogens/Prenatal Substance Abuse". Understanding Genetics: A New England Guide for Patients and Health Professionals. Genetic Alliance.
  107. ^ "Press Announcements – FDA issues final rule on changes to pregnancy and lactation labeling information for prescription drug and biological products". www.fda.gov. from the original on 17 November 2015. Retrieved 16 November 2015.
  108. ^ "Basics about FASDs". CDC. Retrieved 25 July 2018.
  109. ^ Hackshaw A, Rodeck C, Boniface S (September–October 2011). "Maternal smoking in pregnancy and birth defects: a systematic review based on 173 687 malformed cases and 11.7 million controls". Human Reproduction Update. 17 (5): 589–604. doi:10.1093/humupd/dmr022. PMC 3156888. PMID 21747128.
  110. ^ Centers for Disease Control and Prevention. 2007. Preventing Smoking and Exposure to Secondhand Smoke Before, During, and After Pregnancy 11 September 2011 at the Wayback Machine.
  111. ^ "Tobacco Use and Pregnancy – Reproductive Health". www.cdc.gov. 16 January 2019. from the original on 29 July 2017.
  112. ^ a b . North Dakota Department of Health. Archived from the original on 10 September 2011. Retrieved 7 October 2011.
  113. ^ Della Grotta S, LaGasse LL, Arria AM, Derauf C, Grant P, Smith LM, et al. (July 2010). "Patterns of methamphetamine use during pregnancy: results from the Infant Development, Environment, and Lifestyle (IDEAL) Study". Maternal and Child Health Journal. 14 (4): 519–527. doi:10.1007/s10995-009-0491-0. PMC 2895902. PMID 19565330.
  114. ^ Martin R, Dombrowski SC (2008). "12. Air and Water Pollution". Prenatal exposures: psychological and educational consequences for children. New York: Springer. doi:10.1007/978-0-387-74398-1. ISBN 978-0-387-74398-1.
  115. ^ Byrne CC (2006). "Environmental hazards during pregnancy". Journal of Midwifery and Women's Health. 1 (51): 57–58. doi:10.1016/j.jmwh.2005.09.008. PMID 16402445.
  116. ^ "N95 Respirator Use During Pregnancy – Findings from Recent NIOSH Research | NIOSH Science Blog | Blogs | CDC". blogs.cdc.gov. from the original on 16 November 2016. Retrieved 16 November 2016.
  117. ^ Boston, 677 Huntington Avenue; Ma 02115 +1495‑1000 (21 October 2022). "Homicide leading cause of death for pregnant women in U.S." News. Retrieved 8 November 2022.
  118. ^ "With homicide a leading cause of maternal death, doctors urged to screen pregnant women for domestic violence". CNN Health. 20 October 2022. Retrieved 8 November 2022.
  119. ^ Wallace, Maeve E. (2022). "Trends in Pregnancy-Associated Homicide, United States, 2020". American Journal of Public Health. 112 (9): 1333–1336. doi:10.2105/AJPH.2022.306937. PMC 9382166. PMID 35797500. Retrieved 8 November 2022.
  120. ^ a b c Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS, eds. (2014). . Williams Obstetrics (24th ed.). New York: McGraw-Hill Education. ISBN 978-0-07-179893-8. Archived from the original on 31 December 2018. Retrieved 9 November 2015.
  121. ^ Bermudez MP, Sanchez AI, Buela-Casal G (2001). "Influence of the Gestation Period on Sexual Desire". Psychology in Spain. 5 (1): 14–16. from the original on 9 February 2012.
  122. ^ Fok WY, Chan LY, Yuen PM (October 2005). "Sexual behavior and activity in Chinese pregnant women". Acta Obstetricia et Gynecologica Scandinavica. 84 (10): 934–938. doi:10.1111/j.0001-6349.2005.00743.x. PMID 16167907. S2CID 23075166.
  123. ^ Reamy K, White SE, Daniell WC, Le Vine ES (June 1982). "Sexuality and pregnancy. A prospective study". The Journal of Reproductive Medicine. 27 (6): 321–327. PMID 7120209.
  124. ^ Malarewicz A, Szymkiewicz J, Rogala J (September 2006). "[Sexuality of pregnant women]". Ginekologia Polska (in Polish). 77 (9): 733–739. PMID 17219804.
  125. ^ Kramer MS, McDonald SW (July 2006). Kramer MS (ed.). "Aerobic exercise for women during pregnancy". The Cochrane Database of Systematic Reviews. 3 (3): CD000180. doi:10.1002/14651858.CD000180.pub2. PMC 7043271. PMID 16855953.
  126. ^ Domenjoz I, Kayser B, Boulvain M (October 2014). "Effect of physical activity during pregnancy on mode of delivery". American Journal of Obstetrics and Gynecology. 211 (4): 401.e1–401.11. doi:10.1016/j.ajog.2014.03.030. PMID 24631706.
  127. ^ a b Beetham KS, Giles C, Noetel M, Clifton V, Jones JC, Naughton G (August 2019). "The effects of vigorous intensity exercise in the third trimester of pregnancy: a systematic review and meta-analysis". BMC Pregnancy and Childbirth. 19 (1): 281. doi:10.1186/s12884-019-2441-1. PMC 6686535. PMID 31391016.
  128. ^ Di Mascio D, Magro-Malosso ER, Saccone G, Marhefka GD, Berghella V (November 2016). "Exercise during pregnancy in normal-weight women and risk of preterm birth: a systematic review and meta-analysis of randomized controlled trials". American Journal of Obstetrics and Gynecology. 215 (5): 561–571. doi:10.1016/j.ajog.2016.06.014. hdl:11573/1110770. PMID 27319364. S2CID 32419788.
  129. ^ McCall CA, Grimes DA, Lyerly AD (June 2013). ""Therapeutic" bed rest in pregnancy: unethical and unsupported by data". Obstetrics and Gynecology. 121 (6): 1305–1308. doi:10.1097/aog.0b013e318293f12f. PMID 23812466.
  130. ^ Davies GA, Wolfe LA, Mottola MF, MacKinnon C, Arsenault MY, Bartellas E, et al. (June 2003). "Exercise in pregnancy and the postpartum period". Journal of Obstetrics and Gynaecology Canada. 25 (6): 516–529. doi:10.1016/s1701-2163(16)30313-9. PMID 12806453.
  131. ^ a b c Artal R, O'Toole M (February 2003). "Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period". British Journal of Sports Medicine. 37 (1): 6–12, discussion 12. doi:10.1136/bjsm.37.1.6. PMC 1724598. PMID 12547738.
  132. ^ Reiter RJ, Tan DX, Korkmaz A, Rosales-Corral SA (2014). "Melatonin and stable circadian rhythms optimize maternal, placental and fetal physiology". Human Reproduction Update. 20 (2): 293–307. doi:10.1093/humupd/dmt054. PMID 24132226.
  133. ^ (PDF). Archived from the original (PDF) on 22 August 2018. Retrieved 2 June 2018.
  134. ^ Jafarzadeh H, Sanatkhani M, Mohtasham N (December 2006). "Oral pyogenic granuloma: a review". Journal of Oral Science. 48 (4): 167–175. doi:10.2334/josnusd.48.167. PMID 17220613.
  135. ^ Iheozor-Ejiofor Z, Middleton P, Esposito M, Glenny AM (June 2017). "Treating periodontal disease for preventing adverse birth outcomes in pregnant women". The Cochrane Database of Systematic Reviews. 2017 (6): CD005297. doi:10.1002/14651858.CD005297.pub3. PMC 6481493. PMID 28605006.
  136. ^ Howland G (2017). The Mama Natural Week-by-Week Guide to Pregnancy and Childbirth. Simon and Schuster. p. 173. ISBN 9781501146688.
  137. ^ a b c Jarvis S, Stone J, Eddleman K, Duenwald M (2011). Pregnancy For Dummies. John Wiley & Sons. p. 157. ISBN 9781119997061.
  138. ^ . Transportation Security Administration. 22 July 2014. Archived from the original on 6 August 2020. Retrieved 27 February 2019.
  139. ^ "Antenatal classes". NHS. December 2020. Retrieved 16 November 2022.
  140. ^ "Promoting baby-friendly hospitals". World Health Organization. Retrieved 16 November 2022.
  141. ^ . World Health Organization Regional Office for South-East Asia. 2009. Archived from the original on 15 December 2009. Retrieved 7 December 2009.
  142. ^ "Pregnancy complicated by disease". Merck Manual, Home Health Handbook. Merck Sharp & Dohme.
  143. ^ Stewart DE, Vigod S (December 2016). "Postpartum Depression". The New England Journal of Medicine. 375 (22): 2177–2186. doi:10.1056/nejmcp1607649. PMID 27959754.
  144. ^ Lara A Friel. "Thromboembolic Disorders During Pregnancy". Merck Sharp & Dohme Corp.
  145. ^ a b Leveno K (2013). "52". Williams Manual of Pregnancy Complications. New York: McGraw-Hill Medical. pp. 323–334. ISBN 978-0-07-176562-6.
  146. ^ "What are the symptoms of pregnancy loss (before 20 weeks of pregnancy)?". NIH. Retrieved 4 October 2022.
  147. ^ "Miscarriage Causes". WebMD. Retrieved 6 October 2022.
  148. ^ "What Is Stillborn". CDC. 29 September 2022. Retrieved 6 October 2022.
  149. ^ "Miscarriage". NHS. {{cite web}}: Missing or empty |url= (help)
  150. ^ Obst, K. L.; Due, C.; Oxlad, M.; Middleton, P. (2020). "Men's grief following pregnancy loss and neonatal loss: a systematic review and emerging theoretical model". BMC Pregnancy and Childbirth. 20 (1): 11. doi:10.1186/s12884-019-2677-9. PMC 6953275. PMID 31918681.
  151. ^ Tersigni C, Castellani R, de Waure C, Fattorossi A, De Spirito M, Gasbarrini A, et al. (2014). "Celiac disease and reproductive disorders: meta-analysis of epidemiologic associations and potential pathogenic mechanisms". Human Reproduction Update. 20 (4): 582–593. doi:10.1093/humupd/dmu007. PMID 24619876.
  152. ^ Saccone G, Berghella V, Sarno L, Maruotti GM, Cetin I, Greco L, et al. (February 2016). "Celiac disease and obstetric complications: a systematic review and metaanalysis". American Journal of Obstetrics and Gynecology. 214 (2): 225–234. doi:10.1016/j.ajog.2015.09.080. PMID 26432464.
  153. ^ "The Gluten Connection". Health Canada. May 2009. from the original on 5 July 2017. Retrieved 1 October 2013.
  154. ^ a b Page 264 in: Gresele, Paolo (2008). Platelets in hematologic and cardiovascular disorders: a clinical handbook. Cambridge, UK: Cambridge University Press. ISBN 978-0-521-88115-9.
  155. ^ Zdanowicz C (21 May 2019). "Women have abortions for many reasons aside from rape and incest. Here are some of them". CNN. Retrieved 2 July 2022.
  156. ^ "Law and Policy Guide: Rape and Incest Exceptions". Center for Reproductive Rights. 18 January 2022. Retrieved 2 July 2022.
  157. ^ "SDG Indicator 3.7.1 on Contraceptive Use". Population Division. Retrieved 3 July 2022.
  158. ^ a b c "Guidelines for Diagnostic Imaging During Pregnancy and Lactation". American Congress of Obstetricians and Gynecologists. from the original on 30 July 2017. February 2016
  159. ^ . cia.gov. Archived from the original on 28 October 2009.
  160. ^ National Vital Statistics Reports 20 July 2017 at the Wayback Machine from Centers for Disease Control and Prevention National Center for Health Statistics. Volume 61, Number 1 August 28, 2012: Births: Final Data for 2010
  161. ^ "40% of pregnancies 'unplanned'". BBC News. 16 March 2004. from the original on 30 July 2012.
  162. ^ Jayson S (20 May 2011). "Unplanned pregnancies in U.S. at 40 percent". PhysOrg.com. from the original on 5 January 2012.
  163. ^ Cherlin AJ (September 2021). "Rising nonmarital first childbearing among college-educated women: Evidence from three national studies". Proceedings of the National Academy of Sciences of the United States of America. 118 (37): e2109016118. Bibcode:2021PNAS..11809016C. doi:10.1073/pnas.2109016118. PMC 8449381. PMID 34493673.
  164. ^ "Maternity and paternity at work: Law and practice across the world". International Labour Organization. Retrieved 3 September 2022.
  165. ^ Katie Mcdonough (30 April 2014). "Tennessee just became the first state that will jail women for their pregnancy outcomes". Salon. from the original on 5 May 2014. Retrieved 5 May 2014.
  166. ^ a b "NONFICTION: When Pregnancy is a Crime". 17 June 2021.
  167. ^ "Employment of Foreign Manpower (Work Passes) Regulations 2012 - Singapore Statutes Online".
  168. ^ "Employment of Foreign Manpower Act - Singapore Statutes Online".
  169. ^ "Employers will not lose security bond if FDW gets pregnant – MOM". twc2.org.sg. 1 July 2011. Retrieved 15 December 2021.
  170. ^ a b "Adolescent pregnancy". World Health Organization. Retrieved 26 October 2022.
  171. ^ "Adolescent health". www.who.int.
  172. ^ "What Are the Effects of Teenage Pregnancy?". Healthline. 19 September 2016. Retrieved 26 October 2022.
  173. ^ "The Adverse Effects of Teen Pregnancy". youth.gov. Retrieved 26 October 2022.
  174. ^ Bekaert, S.; Smithbattle, L. (2016). "Teen Mothers' Experience of Intimate Partner Violence: A Metasynthesis". Ans. Advances in Nursing Science. 39 (3): 272–290. doi:10.1097/ANS.0000000000000129. PMID 27490882. S2CID 10471475. Retrieved 26 October 2022.
  175. ^ "Nurse-Family Partnership". Social Programs that Work. Retrieved 4 December 2022.
  176. ^ Miller, Claire Cain (25 July 2017). "How Home Visits by Nurses Help Mothers and Children, Especially Boys". The New York Times. Retrieved 6 December 2022.
  177. ^ Pereira GM, Pimentel VM, Surita FG, Silva AD, Brito LG (2022). "Perceived racism or racial discrimination and the risk of adverse obstetric outcomes: a systematic review". Sao Paulo Med J. 140 (5): 705–718. doi:10.1590/1516-3180.2021.0505.R1.07042022. PMC 9514866. PMID 36043663.
  178. ^ a b Guerra-Reyes L, Hamilton LJ (February 2017). "Racial disparities in birth care: Exploring the perceived role of African-American women providing midwifery care and birth support in the United States". Women and Birth. 30 (1): e9–e16. doi:10.1016/j.wombi.2016.06.004. PMID 27364419.
  179. ^ Obedin-Maliver, Juno; Makadon, Harvey J (2016). "Transgender men and pregnancy". Obstetric Medicine. 9 (1): 4–8. doi:10.1177/1753495X15612658. PMC 4790470. PMID 27030799.
  180. ^ Light AD, Obedin-Maliver J, Sevelius JM, Kerns JL (December 2014). "Transgender men who experienced pregnancy after female-to-male gender transitioning". Obstetrics and Gynecology. 124 (6): 1120–1127. doi:10.1097/AOG.0000000000000540. PMID 25415163. S2CID 36023275.
  181. ^ Womack M (2010). The anthropology of health and healing. Plymouth: AltaMira Press. p. 133. ISBN 978-0-7591-1044-1.
  182. ^ Rossi TV (2005). Mary in western art. New York: In Association with Hudson Hills Press. p. 106. ISBN 978-0-9712981-9-4.

Further reading

  • "Nutrition for the First Trimester of Pregnancy". IDEA Health & Fitness Association. Retrieved 9 December 2013.
  • Bothwell TH (July 2000). "Iron requirements in pregnancy and strategies to meet them". The American Journal of Clinical Nutrition. 72 (1 Suppl): 257S–264S. doi:10.1093/ajcn/72.1.257S. PMID 10871591.
  • Stevens J (June 2005). "Pregnancy envy and the politics of compensatory masculinities". Politics & Gender. 1 (2): 265–296. CiteSeerX 10.1.1.485.5791. doi:10.1017/S1743923X05050087. S2CID 39231847.

External links

 
Wikimedia Commons has media related to Human pregnancy.
 
Wikiquote has quotations related to Pregnancy.
  • Pregnancy at Curlie
  • Merck Manual Home Health Handbook – further details on the diseases, disorders, etc., which may complicate pregnancy.
  • Pregnancy care – NHS guide to having a baby including preconception, pregnancy, labor, and birth.

March 20, 2023
pregnancy, this, article, about, pregnancy, humans, other, mammals, mammals, fish, fish, trimester, pregnancy, redirects, here, other, uses, trimester, trimester, time, during, which, more, offspring, develops, gestates, inside, woman, uterus, womb, multiple, . This article is about pregnancy in humans For other mammals see Pregnancy mammals For fish see Pregnancy in fish Trimester pregnancy redirects here For other uses of trimester see Trimester Pregnancy is the time during which one or more offspring develops gestates inside a woman s uterus womb 4 13 A multiple pregnancy involves more than one offspring such as with twins 14 PregnancyOther namesGestationA woman in the third trimester of pregnancySpecialtyObstetrics midwiferySymptomsMissed periods tender breasts nausea and vomiting hunger frequent urination 1 ComplicationsMiscarriage high blood pressure of pregnancy gestational diabetes iron deficiency anemia severe nausea and vomiting 2 3 Duration 40 weeks from the last menstrual period 38 weeks after conception 4 5 CausesSexual intercourse assisted reproductive technology 6 Diagnostic methodPregnancy test 7 PreventionBirth control including emergency contraception 8 TreatmentPrenatal care 9 abortion 8 MedicationFolic acid iron supplements 9 10 Frequency213 million 2012 11 Deaths230 600 2016 12 Pregnancy usually occurs by sexual intercourse but can also occur through assisted reproductive technology procedures 6 A pregnancy may end in a live birth a miscarriage an induced abortion or a stillbirth Childbirth typically occurs around 40 weeks from the start of the last menstrual period LMP a span known as the gestational age 4 5 This is just over nine months Counting by fertilization age the length is about 38 weeks 5 13 Pregnancy is the presence of an implanted human embryo or fetus in the uterus implantation occurs on average 8 9 days after fertilization 15 An embryo is the term for the developing offspring during the first seven weeks following implantation i e ten weeks gestational age after which the term fetus is used until birth 5 Signs and symptoms of early pregnancy may include missed periods tender breasts morning sickness nausea and vomiting hunger implantation bleeding and frequent urination 1 Pregnancy may be confirmed with a pregnancy test 7 Methods of birth control or more accurately contraception are used to avoid pregnancy Pregnancy is divided into three trimesters of approximately three months each The first trimester includes conception which is when the sperm fertilizes the egg The fertilized egg then travels down the Fallopian tube and attaches to the inside of the uterus where it begins to form the embryo and placenta During the first trimester the possibility of miscarriage natural death of embryo or fetus is at its highest Around the middle of the second trimester movement of the fetus may be felt At 28 weeks more than 90 of babies can survive outside of the uterus if provided with high quality medical care though babies born at this time will likely experience serious health complications such as heart and respiratory problems and long term intellectual and developmental disabilities Prenatal care improves pregnancy outcomes 9 Nutrition during pregnancy is important to ensure healthy growth of the fetus 16 Prenatal care may also include avoiding recreational drugs including tobacco and alcohol taking regular exercise having blood tests and regular physical examinations 9 Complications of pregnancy may include disorders of high blood pressure gestational diabetes iron deficiency anemia and severe nausea and vomiting 3 In the ideal childbirth labor begins on its own at term 17 Babies born before 37 weeks are preterm and at higher risk of health problems such as cerebral palsy 4 Babies born between weeks 37 and 39 are considered early term while those born between weeks 39 and 41 are considered full term 4 Babies born between weeks 41 and 42 weeks are considered late term while after 42 weeks they are considered post term 4 Delivery before 39 weeks by labor induction or caesarean section is not recommended unless required for other medical reasons 18 About 213 million pregnancies occurred in 2012 of which 190 million 89 were in the developing world and 23 million 11 were in the developed world 11 The number of pregnancies in women aged between 15 and 44 is 133 per 1 000 women 11 About 10 to 15 of recognized pregnancies end in miscarriage 2 In 2016 complications of pregnancy resulted in 230 600 maternal deaths down from 377 000 deaths in 1990 12 Common causes include bleeding infections hypertensive diseases of pregnancy obstructed labor miscarriage abortion or ectopic pregnancy 12 Globally 44 of pregnancies are unplanned 19 Over half 56 of unplanned pregnancies are aborted 19 Among unintended pregnancies in the United States 60 of the women used birth control to some extent during the month pregnancy began 20 Contents 1 Terminology 2 Signs and symptoms 3 Timeline 3 1 Start of gestational age 3 2 Trimesters 3 3 Estimation of due date 4 Physiology 4 1 Capacity 4 2 Initiation 4 3 Development of embryo and fetus 4 4 Maternal changes 4 5 Childbirth 4 5 1 Childbirth maturity stages 4 6 Postnatal period 5 Diagnosis 5 1 Physical signs 5 2 Biomarkers 5 3 Ultrasound 6 Management 6 1 Prenatal care 6 2 Nutrition 6 3 Weight gain 6 4 Medication 6 5 Recreational drugs 6 6 Exposure to toxins 6 7 Death by violence 6 8 Sexual activity 6 9 Exercise 6 10 Sleep 6 11 Dental care 6 12 Flying 6 13 Pregnancy classes and birth plan 7 Complications 7 1 Miscarriage and stillbirth 8 Diseases in pregnancy 9 Abortion 10 Birth control and education 11 Technologies and science 11 1 Assisted reproductive technology 11 2 Medical imaging 12 Epidemiology 13 Legal and social aspects 13 1 Legal protection 13 2 Teenage pregnancy 13 3 Racial disparities 13 4 Transgender people 14 Culture 14 1 Arts 15 See also 16 References 17 Further reading 18 External linksTerminology William Hunter Anatomia uteri humani gravidi tabulis illustrata 1774 Associated terms for pregnancy are gravid and parous Gravidus and gravid come from the Latin word meaning heavy and a pregnant female is sometimes referred to as a gravida 21 Gravidity refers to the number of times that a female has been pregnant Similarly the term parity is used for the number of times that a female carries a pregnancy to a viable stage 22 Twins and other multiple births are counted as one pregnancy and birth A woman who has never been pregnant is referred to as a nulligravida A woman who is or has been only pregnant for the first time is referred to as a primigravida 23 and a woman in subsequent pregnancies as a multigravida or as multiparous 21 24 Therefore during a second pregnancy a woman would be described as gravida 2 para 1 and upon live delivery as gravida 2 para 2 In progress pregnancies abortions miscarriages and or stillbirths account for parity values being less than the gravida number Women who have never carried a pregnancy more than 20 weeks are referred to as nulliparous 25 A pregnancy is considered term at 37 weeks of gestation It is preterm if less than 37 weeks and postterm at or beyond 42 weeks of gestation American College of Obstetricians and Gynecologists have recommended further division with early term 37 weeks up to 39 weeks full term 39 weeks up to 41 weeks and late term 41 weeks up to 42 weeks 26 The terms preterm and postterm have largely replaced earlier terms of premature and postmature Preterm and postterm are defined above whereas premature and postmature have historical meaning and relate more to the infant s size and state of development rather than to the stage of pregnancy 27 28 Signs and symptomsMain article Signs and symptoms of pregnancy Further information Complications of pregnancy Melasma pigment changes to the face due to pregnancy In the later part of pregnancy the uterus takes up much of the abdomen The usual signs and symptoms of pregnancy do not significantly interfere with activities of daily living or pose a health threat to the mother or baby However pregnancy complications can cause other more severe symptoms such as those associated with anemia Common signs and symptoms of pregnancy include Tiredness Morning sickness Constipation Pelvic girdle pain Back pain Braxton Hicks contractions Occasional irregular and often painless contractions that occur several times per day Peripheral edema swelling of the lower limbs Common complaint in advancing pregnancy Can be caused by inferior vena cava syndrome resulting from compression of the inferior vena cava and pelvic veins by the uterus leading to increased hydrostatic pressure in lower extremities Low blood pressure often caused by compression of both the inferior vena cava and the abdominal aorta aortocaval compression syndrome Increased urinary frequency A common complaint caused by increased intravascular volume elevated glomerular filtration rate and compression of the bladder by the expanding uterus Urinary tract infection 29 Varicose veins Common complaint caused by relaxation of the venous smooth muscle and increased intravascular pressure Hemorrhoids piles Swollen veins at or inside the anal area Caused by impaired venous return straining associated with constipation or increased intra abdominal pressure in later pregnancy 30 Regurgitation heartburn and nausea Stretch marks Breast tenderness is common during the first trimester and is more common in women who are pregnant at a young age 31 Melasma also known as the mask of pregnancy is a discoloration most often of the face It usually begins to fade several months after giving birth TimelineComparison of dating systems for a typical pregnancy Event Gestational age from the start of the last menstrual period Fertilization age Implantation ageMenstrual period begins Day 1 of pregnancy Not pregnant Not pregnantHas sex and ovulates 2 weeks pregnant Not pregnant Not pregnantFertilization cleavage stage begins 32 Day 15 32 Day 1 32 33 Not pregnantImplantation of blastocyst begins Day 20 Day 6 32 33 Day 0Implantation finished Day 26 Day 12 32 33 Day 6 or Day 0 Embryo stage begins also first missed period 4 weeks Day 15 32 Day 9Primitive heart function can be detected 5 weeks 5 days 32 Day 26 32 Day 20Fetal stage begins 10 weeks 1 day 32 8 weeks 1 day 32 7 weeks 2 daysFirst trimester ends 13 weeks 11 weeks 10 weeksSecond trimester ends 26 weeks 24 weeks 23 weeksChildbirth 39 40 weeks 37 38 weeks 33 108 36 37 weeksThe chronology of pregnancy is unless otherwise specified generally given as gestational age where the starting point is the beginning of the woman s last menstrual period LMP or the corresponding age of the gestation as estimated by a more accurate method if available This model means that the woman is counted as being pregnant two weeks before conception and three weeks before implantation Sometimes timing may also use the fertilization age which is the age of the embryo since conception Start of gestational age Main article Gestational age The American Congress of Obstetricians and Gynecologists recommend the following methods to calculate gestational age 34 Directly calculating the days since the beginning of the last menstrual period Early obstetric ultrasound comparing the size of an embryo or fetus to that of a reference group of pregnancies of known gestational age such as calculated from last menstrual periods and using the mean gestational age of other embryos or fetuses of the same size If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period it is still the one from the early ultrasound that is used for the rest of the pregnancy 34 In case of in vitro fertilization calculating days since oocyte retrieval or co incubation and adding 14 days 35 Trimesters Pregnancy is divided into three trimesters each lasting for approximately three months 4 The exact length of each trimester can vary between sources A typical pregnancy lasts about a year The first trimester begins with the start of gestational age as described above that is the beginning of week 1 or 0 weeks 0 days of gestational age GA It ends at week 12 11 weeks 6 days of GA 4 or end of week 14 13 weeks 6 days of GA 36 The second trimester is defined as starting between the beginning of week 13 12 weeks 0 days of GA 4 and beginning of week 15 14 weeks 0 days of GA 36 It ends at the end of week 27 26 weeks 6 days of GA 36 or end of week 28 27 weeks 6 days of GA 4 The third trimester is defined as starting between the beginning of week 28 27 weeks 0 days of GA 36 or beginning of week 29 28 weeks 0 days of GA 4 It lasts until childbirth Timeline of pregnancy including from top to bottom Trimesters embryo fetus development gestational age in weeks and months viability and maturity stages Estimation of due date Distribution of gestational age at childbirth among singleton live births given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period 37 Roughly 80 of births occur between 37 and 41 weeks of gestational age Main article Estimated date of delivery Due date estimation basically follows two steps Determination of which time point is to be used as origin for gestational age as described in the section above Adding the estimated gestational age at childbirth to the above time point Childbirth on average occurs at a gestational age of 280 days 40 weeks which is therefore often used as a standard estimation for individual pregnancies 38 However alternative durations as well as more individualized methods have also been suggested The American College of Obstetricians and Gynecologists divides full term into three divisions 39 Early term 37 weeks and 0 days through 38 weeks and 6 days Full term 39 weeks and 0 days through 40 weeks and 6 days Late term 41 weeks and 0 days through 41 weeks and 6 days Post term greater than or equal to 42 weeks and 0 daysNaegele s rule is a standard way of calculating the due date for a pregnancy when assuming a gestational age of 280 days at childbirth The rule estimates the expected date of delivery EDD by adding a year subtracting three months and adding seven days to the origin of gestational age Alternatively there are mobile apps which essentially always give consistent estimations compared to each other and correct for leap year while pregnancy wheels made of paper can differ from each other by 7 days and generally do not correct for leap year 40 Furthermore actual childbirth has only a certain probability of occurring within the limits of the estimated due date A study of singleton live births came to the result that childbirth has a standard deviation of 14 days when gestational age is estimated by first trimester ultrasound and 16 days when estimated directly by last menstrual period 37 PhysiologyCapacity Further information Pregnancy over age 50 Fertility and fecundity are the respective capacities to fertilize and establish a clinical pregnancy and have a live birth Infertility is an impaired ability to establish a clinical pregnancy and sterility is the permanent inability to establish a clinical pregnancy 41 The capacity for pregnancy depends on the reproductive system its development and its variation as well as on the condition of a person Women as well as intersex and transgender people who have a functioning female reproductive system are capable of pregnancy In some cases someone might be able to produce fertilizable eggs but might not have a womb or none that can sufficiently gestate in which case they might find surrogacy 42 Initiation See also Human fertilization Fertilization and implantation in humans Through an interplay of hormones that includes follicle stimulating hormone that stimulates folliculogenesis and oogenesis creates a mature egg cell the female gamete Fertilization is the event where the egg cell fuses with the male gamete spermatozoon After the point of fertilization the fused product of the female and male gamete is referred to as a zygote or fertilized egg The fusion of female and male gametes usually occurs following the act of sexual intercourse Pregnancy rates for sexual intercourse are highest during the menstrual cycle time from some 5 days before until 1 to 2 days after ovulation 43 Fertilization can also occur by assisted reproductive technology such as artificial insemination and in vitro fertilisation Fertilization conception is sometimes used as the initiation of pregnancy with the derived age being termed fertilization age Fertilization usually occurs about two weeks before the next expected menstrual period A third point in time is also considered by some people to be the true beginning of a pregnancy This is time of implantation when the future fetus attaches to the lining of the uterus This is about a week to ten days after fertilization 44 Development of embryo and fetus Main articles Human embryonic development Prenatal development and Fetus The initial stages of human embryogenesis The sperm and the egg cell which has been released from one of the female s two ovaries unite in one of the two Fallopian tubes The fertilized egg known as a zygote then moves toward the uterus a journey that can take up to a week to complete Cell division begins approximately 24 to 36 hours after the female and male cells unite Cell division continues at a rapid rate and the cells then develop into what is known as a blastocyst The blastocyst arrives at the uterus and attaches to the uterine wall a process known as implantation The development of the mass of cells that will become the infant is called embryogenesis during the first approximately ten weeks of gestation During this time cells begin to differentiate into the various body systems The basic outlines of the organ body and nervous systems are established By the end of the embryonic stage the beginnings of features such as fingers eyes mouth and ears become visible Also during this time there is development of structures important to the support of the embryo including the placenta and umbilical cord The placenta connects the developing embryo to the uterine wall to allow nutrient uptake waste elimination and gas exchange via the mother s blood supply The umbilical cord is the connecting cord from the embryo or fetus to the placenta After about ten weeks of gestational age which is the same as eight weeks after conception the embryo becomes known as a fetus 45 At the beginning of the fetal stage the risk of miscarriage decreases sharply 46 At this stage a fetus is about 30 mm 1 2 inches in length the heartbeat is seen via ultrasound and the fetus makes involuntary motions 47 During continued fetal development the early body systems and structures that were established in the embryonic stage continue to develop Sex organs begin to appear during the third month of gestation The fetus continues to grow in both weight and length although the majority of the physical growth occurs in the last weeks of pregnancy Electrical brain activity is first detected at the end of week 5 of gestation but as in brain dead patients it is primitive neural activity rather than the beginning of conscious brain activity Synapses do not begin to form until week 17 48 Neural connections between the sensory cortex and thalamus develop as early as 24 weeks gestational age but the first evidence of their function does not occur until around 30 weeks when minimal consciousness dreaming and the ability to feel pain emerges 49 Although the fetus begins to move during the first trimester it is not until the second trimester that movement known as quickening can be felt This typically happens in the fourth month more specifically in the 20th to 21st week or by the 19th week if the woman has been pregnant before It is common for some women not to feel the fetus move until much later During the second trimester when the body size changes maternity clothes may be worn Embryo at 4 weeks after fertilization gestational age of 6 weeks Fetus at 8 weeks after fertilization gestational age of 10 weeks Fetus at 18 weeks after fertilization gestational age of 20 weeks Fetus at 38 weeks after fertilization gestational age of 40 weeks Relative size in 1st month simplified illustration Relative size in 3rd month simplified illustration Relative size in 5th month simplified illustration Relative size in 9th month simplified illustration Maternal changes The uterus expands making up a larger and larger portion of the abdomen During the final stages of gestation the uterus may drop to a lower position Main article Maternal physiological changes in pregnancy Breast changes as seen during pregnancy The areolae are larger and darker During pregnancy a woman undergoes many physiological changes which are entirely normal including behavioral cardiovascular hematologic metabolic renal and respiratory changes Increases in blood sugar breathing and cardiac output are all required Levels of progesterone and estrogens rise continually throughout pregnancy suppressing the hypothalamic axis and therefore also the menstrual cycle A full term pregnancy at an early age lt 25 reduces the risk of breast ovarian and endometrial cancer and the risk declines further with each additional full term pregnancy 50 51 End of second trimester 2 weeks 26 weeks of pregnancy The fetus is genetically different from its mother and can be viewed as an unusually successful allograft 52 The main reason for this success is increased immune tolerance during pregnancy 53 Immune tolerance is the concept that the body is able to not mount an immune system response against certain triggers 52 During the first trimester minute ventilation increases by 40 54 The womb will grow to the size of a lemon by eight weeks Many symptoms and discomforts of pregnancy like nausea and tender breasts appear in the first trimester 55 During the second trimester most women feel more energized and begin to put on weight as the symptoms of morning sickness subside and eventually fade away The uterus the muscular organ that holds the developing fetus can expand up to 20 times its normal size during pregnancy Braxton Hicks contractions are sporadic uterine contractions that may start around six weeks into a pregnancy however they are usually not felt until the second or third trimester 56 Final weight gain takes place during the third trimester which is the most weight gain throughout the pregnancy The woman s abdomen will transform in shape as it drops due to the fetus turning in a downward position ready for birth During the second trimester the woman s abdomen would have been upright whereas in the third trimester it will drop down low The fetus moves regularly and is felt by the woman Fetal movement can become strong and be disruptive to the woman The woman s navel will sometimes become convex popping out due to the expanding abdomen Third trimester pregnant woman Head engagement also called lightening or dropping occurs as the fetal head descends into a cephalic presentation While it relieves pressure on the upper abdomen and gives a renewed ease in breathing it also severely reduces bladder capacity resulting in a need to void more frequently and increases pressure on the pelvic floor and the rectum It is not possible to predict when lightening occurs In a first pregnancy it may happen a few weeks before the due date though it may happen later or even not until labor begins as is typical with subsequent pregnancies 57 It is also during the third trimester that maternal activity and sleep positions may affect fetal development due to restricted blood flow For instance the enlarged uterus may impede blood flow by compressing the vena cava when lying flat which is relieved by lying on the left side 58 Childbirth Main article Childbirth Childbirth referred to as labor and delivery in the medical field is the process whereby an infant is born 59 A woman is considered to be in labour when she begins experiencing regular uterine contractions accompanied by changes of her cervix primarily effacement and dilation While childbirth is widely experienced as painful some women do report painless labours while others find that concentrating on the birth helps to quicken labour and lessen the sensations Most births are successful vaginal births but sometimes complications arise and a woman may undergo a cesarean section During the time immediately after birth both the mother and the baby are hormonally cued to bond the mother through the release of oxytocin a hormone also released during breastfeeding Studies show that skin to skin contact between a mother and her newborn immediately after birth is beneficial for both the mother and baby A review done by the World Health Organization found that skin to skin contact between mothers and babies after birth reduces crying improves mother infant interaction and helps mothers to breastfeed successfully They recommend that neonates be allowed to bond with the mother during their first two hours after birth the period that they tend to be more alert than in the following hours of early life 60 Childbirth maturity stages Further information Preterm birth and Postterm pregnancy Stages of pregnancy term stage starts endsPreterm 61 at 37 weeksEarly term 62 37 weeks 39 weeksFull term 62 39 weeks 41 weeksLate term 62 41 weeks 42 weeksPostterm 62 42 weeks In the ideal childbirth labor begins on its own when a woman is at term 17 Events before completion of 37 weeks are considered preterm 61 Preterm birth is associated with a range of complications and should be avoided if possible 63 Sometimes if a woman s water breaks or she has contractions before 39 weeks birth is unavoidable 62 However spontaneous birth after 37 weeks is considered term and is not associated with the same risks of a preterm birth 59 Planned birth before 39 weeks by caesarean section or labor induction although at term results in an increased risk of complications 64 This is from factors including underdeveloped lungs of newborns infection due to underdeveloped immune system feeding problems due to underdeveloped brain and jaundice from underdeveloped liver 65 Babies born between 39 and 41 weeks gestation have better outcomes than babies born either before or after this range 62 This special time period is called full term 62 Whenever possible waiting for labor to begin on its own in this time period is best for the health of the mother and baby 17 The decision to perform an induction must be made after weighing the risks and benefits but is safer after 39 weeks 17 Events after 42 weeks are considered postterm 62 When a pregnancy exceeds 42 weeks the risk of complications for both the woman and the fetus increases significantly 66 67 Therefore in an otherwise uncomplicated pregnancy obstetricians usually prefer to induce labour at some stage between 41 and 42 weeks 68 Postnatal period Main article Postpartum period The postpartum period also referred to as the puerperium is the postnatal period that begins immediately after delivery and extends for about six weeks 59 During this period the mother s body begins the return to pre pregnancy conditions that includes changes in hormone levels and uterus size 59 DiagnosisThe beginning of pregnancy may be detected either based on symptoms by the woman herself or by using pregnancy tests However an important condition with serious health implications that is quite common is the denial of pregnancy by the pregnant woman About 1 in 475 denials will last until around the 20th week of pregnancy The proportion of cases of denial persisting until delivery is about 1 in 2500 69 Conversely some non pregnant women have a very strong belief that they are pregnant along with some of the physical changes This condition is known as a false pregnancy 70 Physical signs Further information Symptoms and discomforts of pregnancy Linea nigra in a woman at 22 weeks pregnant Most pregnant women experience a number of symptoms 71 which can signify pregnancy A number of early medical signs are associated with pregnancy 72 73 These signs include the presence of human chorionic gonadotropin hCG in the blood and urine missed menstrual period implantation bleeding that occurs at implantation of the embryo in the uterus during the third or fourth week after last menstrual period increased basal body temperature sustained for over two weeks after ovulation Chadwick s sign darkening of the cervix vagina and vulva Goodell s sign softening of the vaginal portion of the cervix Hegar s sign softening of the uterine isthmus Pigmentation of the linea alba linea nigra darkening of the skin in a midline of the abdomen resulting from hormonal changes usually appearing around the middle of pregnancy 72 73 Darkening of the nipples and areolas due to an increase in hormones 74 Biomarkers Further information Pregnancy test Pregnancy detection can be accomplished using one or more various pregnancy tests 75 which detect hormones generated by the newly formed placenta serving as biomarkers of pregnancy 76 Blood and urine tests can detect pregnancy 12 days after implantation 77 Blood pregnancy tests are more sensitive than urine tests giving fewer false negatives 78 Home pregnancy tests are urine tests and normally detect a pregnancy 12 to 15 days after fertilization 79 A quantitative blood test can determine approximately the date the embryo was conceived because hCG doubles every 36 to 48 hours 59 A single test of progesterone levels can also help determine how likely a fetus will survive in those with a threatened miscarriage bleeding in early pregnancy 80 Ultrasound Main article Obstetric ultrasonography Obstetric ultrasonography can detect fetal abnormalities detect multiple pregnancies and improve gestational dating at 24 weeks 81 The resultant estimated gestational age and due date of the fetus are slightly more accurate than methods based on last menstrual period 82 Ultrasound is used to measure the nuchal fold in order to screen for Down syndrome 83 Management Flowchart showing the recommended weight limits for lifting at work during pregnancy as a function of lifting frequency weeks of gestation and the position of the lifted object relative to the lifter s body 84 85 Prenatal care Main articles Prenatal care and pre conception counseling Pre conception counseling is care that is provided to a woman or couple to discuss conception pregnancy current health issues and recommendations for the period before pregnancy 86 Prenatal medical care is the medical and nursing care recommended for women during pregnancy time intervals and exact goals of each visit differ by country 87 Women who are high risk have better outcomes if they are seen regularly and frequently by a medical professional than women who are low risk 88 A woman can be labeled as high risk for different reasons including previous complications in pregnancy complications in the current pregnancy current medical diseases or social issues 89 90 The aim of good prenatal care is prevention early identification and treatment of any medical complications 91 A basic prenatal visit consists of measurement of blood pressure fundal height weight and fetal heart rate checking for symptoms of labor and guidance for what to expect next 86 Nutrition Main article Nutrition and pregnancy Nutrition during pregnancy is important to ensure healthy growth of the fetus 16 Nutrition during pregnancy is different from the non pregnant state 16 There are increased energy requirements and specific micronutrient requirements 16 Women benefit from education to encourage a balanced energy and protein intake during pregnancy 92 Some women may need professional medical advice if their diet is affected by medical conditions food allergies or specific religious ethical beliefs 93 Further studies are needed to access the effect of dietary advice to prevent gestational diabetes although low quality evidence suggests some benefit 94 Adequate periconceptional time before and right after conception folic acid also called folate or Vitamin B9 intake has been shown to decrease the risk of fetal neural tube defects such as spina bifida 95 The neural tube develops during the first 28 days of pregnancy a urine pregnancy test is not usually positive until 14 days post conception explaining the necessity to guarantee adequate folate intake before conception 79 96 Folate is abundant in green leafy vegetables legumes and citrus 97 In the United States and Canada most wheat products flour noodles are fortified with folic acid 98 Weight gain The amount of healthy weight gain during a pregnancy varies 99 Weight gain is related to the weight of the baby the placenta extra circulatory fluid larger tissues and fat and protein stores 16 Most needed weight gain occurs later in pregnancy 100 The Institute of Medicine recommends an overall pregnancy weight gain for those of normal weight body mass index of 18 5 24 9 of 11 3 15 9 kg 25 35 pounds having a singleton pregnancy 101 Women who are underweight BMI of less than 18 5 should gain between 12 7 and 18 kg 28 40 lb while those who are overweight BMI of 25 29 9 are advised to gain between 6 8 and 11 3 kg 15 25 lb and those who are obese BMI 30 should gain between 5 9 kg 11 20 lb 102 These values reference the expectations for a term pregnancy During pregnancy insufficient or excessive weight gain can compromise the health of the mother and fetus 100 The most effective intervention for weight gain in underweight women is not clear 100 Being or becoming overweight in pregnancy increases the risk of complications for mother and fetus including cesarean section gestational hypertension pre eclampsia macrosomia and shoulder dystocia 99 Excessive weight gain can make losing weight after the pregnancy difficult 99 103 Some of these complications are risk factors for stroke 104 Around 50 of women of childbearing age in developed countries like the United Kingdom are overweight or obese before pregnancy 103 Diet modification is the most effective way to reduce weight gain and associated risks in pregnancy 103 Medication Main article Pharmaceutical drugs in pregnancy Drugs used during pregnancy can have temporary or permanent effects on the fetus 105 Anything including drugs that can cause permanent deformities in the fetus are labeled as teratogens 106 In the U S drugs were classified into categories A B C D and X based on the Food and Drug Administration FDA rating system to provide therapeutic guidance based on potential benefits and fetal risks 107 Drugs including some multivitamins that have demonstrated no fetal risks after controlled studies in humans are classified as Category A 105 On the other hand drugs like thalidomide with proven fetal risks that outweigh all benefits are classified as Category X 105 Recreational drugs See also Neonatal withdrawal The use of recreational drugs in pregnancy can cause various pregnancy complications 59 Alcoholic drinks consumed during pregnancy can cause one or more fetal alcohol spectrum disorders 59 According to the CDC there is no known safe amount of alcohol during pregnancy and no safe time to drink during pregnancy including before a woman knows that she is pregnant 108 Tobacco smoking during pregnancy can cause a wide range of behavioral neurological and physical difficulties 109 Smoking during pregnancy causes twice the risk of premature rupture of membranes placental abruption and placenta previa 110 Smoking is associated with 30 higher odds of preterm birth 111 Prenatal cocaine exposure is associated with premature birth birth defects and attention deficit disorder 59 Prenatal methamphetamine exposure can cause premature birth and congenital abnormalities 112 Short term neonatal outcomes in methamphetamine babies show small deficits in infant neurobehavioral function and growth restriction 113 Long term effects in terms of impaired brain development may also be caused by methamphetamine use 112 Cannabis in pregnancy has been shown to be teratogenic in large doses in animals but has not shown any teratogenic effects in humans 59 Exposure to toxins Further information Environmental toxicants and fetal development source source source source source source source source source source source source source source track A video describing research on N95 respirator use during advanced pregnancy Intrauterine exposure to environmental toxins in pregnancy has the potential to cause adverse effects on prenatal development and to cause pregnancy complications 59 Air pollution has been associated with low birth weight infants 114 Conditions of particular severity in pregnancy include mercury poisoning and lead poisoning 59 To minimize exposure to environmental toxins the American College of Nurse Midwives recommends checking whether the home has lead paint washing all fresh fruits and vegetables thoroughly and buying organic produce and avoiding cleaning products labeled toxic or any product with a warning on the label 115 Pregnant women can also be exposed to toxins in the workplace including airborne particles The effects of wearing an N95 filtering facepiece respirator are similar for pregnant women as for non pregnant women and wearing a respirator for one hour does not affect the fetal heart rate 116 Death by violence Pregnant women or those who have recently given birth in the U S are more likely to be murdered than to die from obstetric causes These homicides are a combination of intimate partner violence and firearms Health authorities have called the violence a health emergency for pregnant women but say that pregnancy related homicides are preventable if healthcare providers identify those women at risk and offer assistance to them 117 118 119 Sexual activity Main article Sexual activity during pregnancy Most women can continue to engage in sexual activity including sexual intercourse throughout pregnancy 120 Research suggests that during pregnancy both sexual desire and frequency of sexual relations decrease during the first and third trimester with a rise during the second trimester 121 122 I 123 124 Sex during pregnancy is a low risk behavior except when the healthcare provider advises that sexual intercourse be avoided for particular medical reasons 120 For a healthy pregnant woman there is no single safe or right way to have sex during pregnancy 120 Exercise Regular aerobic exercise during pregnancy appears to improve or maintain physical fitness 125 Physical exercise during pregnancy appears to decrease the need for C section 126 and even vigorous exercise carries no significant risks to babies 127 and provides significant health benefits to the mother 128 Bed rest outside of research studies is not recommended as there is no evidence of benefit and potential harm 129 The Clinical Practice Obstetrics Committee of Canada recommends that All women without contraindications should be encouraged to participate in aerobic and strength conditioning exercises as part of a healthy lifestyle during their pregnancy 130 Although an upper level of safe exercise intensity has not been established women who were regular exercisers before pregnancy and who have uncomplicated pregnancies should be able to engage in high intensity exercise programs without a higher risk of prematurity lower birth weight or gestational weight gain 127 In general participation in a wide range of recreational activities appears to be safe with the avoidance of those with a high risk of falling such as horseback riding or skiing or those that carry a risk of abdominal trauma such as soccer or hockey 131 The American College of Obstetricians and Gynecologists reports that in the past the main concerns of exercise in pregnancy were focused on the fetus and any potential maternal benefit was thought to be offset by potential risks to the fetus However they write that more recent information suggests that in the uncomplicated pregnancy fetal injuries are highly unlikely 131 They do however list several circumstances when a woman should contact her healthcare provider before continuing with an exercise program vaginal bleeding dyspnea before exertion dizziness headache chest pain muscle weakness preterm labor decreased fetal movement amniotic fluid leakage and calf pain or swelling to rule out thrombophlebitis 131 Sleep It has been suggested that shift work and exposure to bright light at night should be avoided at least during the last trimester of pregnancy to decrease the risk of psychological and behavioral problems in the newborn 132 Dental care See also Prenatal dental care The increased levels of progesterone and estrogen during pregnancy make gingivitis more likely the gums become edematous red in colour and tend to bleed 133 Also a pyogenic granuloma or pregnancy tumor is commonly seen on the labial surface of the papilla Lesions can be treated by local debridement or deep incision depending on their size and by following adequate oral hygiene measures 134 There have been suggestions that severe periodontitis may increase the risk of having preterm birth and low birth weight however a Cochrane review found insufficient evidence to determine if periodontitis can develop adverse birth outcomes 135 Flying In low risk pregnancies most health care providers approve flying until about 36 weeks of gestational age 136 Most airlines allow pregnant women to fly short distances at less than 36 weeks and long distances at less than 32 weeks 137 Many airlines require a doctor s note that approves flying especially at over 28 weeks 137 During flights the risk of deep vein thrombosis is decreased by getting up and walking occasionally as well as by avoiding dehydration 137 Full body scanners do not use ionizing radiation and are safe in pregnancy 138 Pregnancy classes and birth plan Main article Birthing classes and birth plans To prepare for the birth of the baby health care providers recommend that parents attend antenatal classes during the third trimester of pregnancy Classes include information about the process of labor and birth and the various kinds of births including both vaginal and caesarean delivery the use of forceps and other interventions that may be needed to safely deliver the infant Types of pain relief including relaxation techniques are discussed Partners or others who may plan to support a woman during her labor and delivery learn how to assist in the birth It is also suggested that a birth plan be written at this time A birth plan is a written statement that outlines the desires of the mother during labor and delivery of the baby Discussing the birth plan with the midwife or other care provider gives parents a chance to ask questions and learn more about the process of labour 139 In 1991 the WHO launched the Baby Friendly Hospital Initiative a global program that recognizes birthing centers and hospitals that offer optimal levels of care for giving birth Facilities that have been certified as Baby Friendly accept visits from expecting parents to familiarize them with the facility and the staff 140 ComplicationsMain article Complications of pregnancy Each year ill health as a result of pregnancy is experienced sometimes permanently by more than 20 million women around the world 141 In 2016 complications of pregnancy resulted in 230 600 deaths down from 377 000 deaths in 1990 12 Common causes include bleeding 72 000 infections 20 000 hypertensive diseases of pregnancy 32 000 obstructed labor 10 000 and pregnancy with abortive outcome 20 000 which includes miscarriage abortion and ectopic pregnancy 12 The following are some examples of pregnancy complications Pregnancy induced hypertension Anemia 142 Postpartum depression a common but solvable complication following childbirth that may result from decreased hormonal levels 143 Postpartum psychosis Thromboembolic disorders with an increased risk due to hypercoagulability in pregnancy These are the leading cause of death in pregnant women in the US 144 145 Pruritic urticarial papules and plaques of pregnancy PUPPP a skin disease that develops around the 32nd week Signs are red plaques papules and itchiness around the belly button that then spreads all over the body except for the inside of hands and face Ectopic pregnancy including abdominal pregnancy implantation of the embryo outside the uterus Hyperemesis gravidarum excessive nausea and vomiting that is more severe than normal morning sickness Pulmonary embolism a blood clot that forms in the legs and migrates to the lungs 145 Acute fatty liver of pregnancy is a rare complication thought to be brought about by a disruption in the metabolism of fatty acids by mitochondria There is also an increased susceptibility and severity of certain infections in pregnancy Miscarriage and stillbirth Main articles Miscarriage and Stillbirth See also Miscarriage and grief Miscarriage is the most common complication of early pregnancy It is defined as the loss of an embryo or fetus before it is able to survive independently The most common symptom of miscarriage is vaginal bleeding with or without pain The miscarriage may be evidenced by a clot like material passing through and out of the vagina 146 About 80 of miscarriages occur in the first 12 weeks of pregnancy The underlying cause in about half of cases involves chromosomal abnormalities 147 Stillbirth is defined as fetal death after 20 or 28 weeks of pregnancy depending on the source It results in a baby born without signs of life Each year about 21 000 babies are stillborn in the U S 148 Sadness anxiety and guilt may occur after a miscarriage or a stillbirth Emotional support may help with processing the loss 149 Fathers may experience grief over the loss as well A large study found that there is a need to increase the accessibility of support services available for fathers 150 Diseases in pregnancyFurther information Pre existing disease in pregnancy A pregnant woman may have a pre existing disease which is not directly caused by the pregnancy but may cause complications to develop that include a potential risk to the pregnancy or a disease may develop during pregnancy Diabetes mellitus and pregnancy deals with the interactions of diabetes mellitus not restricted to gestational diabetes and pregnancy Risks for the child include miscarriage growth restriction growth acceleration large for gestational age macrosomia polyhydramnios too much amniotic fluid and birth defects Thyroid disease in pregnancy can if uncorrected cause adverse effects on fetal and maternal well being The deleterious effects of thyroid dysfunction can also extend beyond pregnancy and delivery to affect neurointellectual development in the early life of the child Demand for thyroid hormones is increased during pregnancy which may cause a previously unnoticed thyroid disorder to worsen Untreated celiac disease can cause a miscarriage intrauterine growth restriction small for gestational age low birthweight and preterm birth Often reproductive disorders are the only manifestation of undiagnosed celiac disease and most cases are not recognized Complications or failures of pregnancy cannot be explained simply by malabsorption but by the autoimmune response elicited by the exposure to gluten which causes damage to the placenta The gluten free diet avoids or reduces the risk of developing reproductive disorders in pregnant women with celiac disease 151 152 Also pregnancy can be a trigger for the development of celiac disease in genetically susceptible women who are consuming gluten 153 Lupus in pregnancy confers an increased rate of fetal death in utero miscarriage and of neonatal lupus Hypercoagulability in pregnancy is the propensity of pregnant women to develop thrombosis blood clots Pregnancy itself is a factor of hypercoagulability pregnancy induced hypercoagulability as a physiologically adaptive mechanism to prevent postpartum bleeding 154 However in combination with an underlying hypercoagulable state the risk of thrombosis or embolism may become substantial 154 AbortionMain article Abortion An abortion is the termination of an embryo or fetus via medical method It is usually done within the first trimester sometimes in the second and rarely in the third Reasons for pregnancies being undesired are broad 155 rape being the most legally accepted 156 Birth control and educationMain article Birth control Family planning as well as the availability and use of contraception along with increased comprehensive sex education has enabled many to prevent pregnancies when they are not desired Schemes and funding to support education and the means to prevent pregnancies when they are not intended have been instrumental and are part of the third of the Sustainable Development Goals SDGs advanced by the United Nations 157 Technologies and scienceFurther information Obstetrics Assisted reproductive technology Main article Assisted reproductive technology Modern reproductive medicine offers many forms of assisted reproductive technology for couples who stay childless against their will such as fertility medication artificial insemination in vitro fertilization and surrogacy Medical imaging CT scanning volume rendered in this case confers a radiation dose to the developing fetus A pregnant woman undergoing an ultrasound Ultrasound is used to check on the growth and development of the fetus Main article Medical imaging in pregnancy Medical imaging may be indicated in pregnancy because of pregnancy complications disease or routine prenatal care Medical ultrasonography including obstetric ultrasonography and magnetic resonance imaging MRI without contrast agents are not associated with any risk for the mother or the fetus and are the imaging techniques of choice for pregnant women 158 Projectional radiography CT scan and nuclear medicine imaging result in some degree of ionizing radiation exposure but in most cases the absorbed doses are not associated with harm to the baby 158 At higher dosages effects can include miscarriage birth defects and intellectual disability 158 EpidemiologySee also Pregnancy rate and Advanced maternal age About 213 million pregnancies occurred in 2012 of which 190 million were in the developing world and 23 million were in the developed world 11 This is about 133 pregnancies per 1 000 women aged 15 to 44 11 About 10 to 15 of recognized pregnancies end in miscarriage 2 Globally 44 of pregnancies are unplanned Over half 56 of unplanned pregnancies are aborted In countries where abortion is prohibited or only carried out in circumstances where the mother s life is at risk 48 of unplanned pregnancies are aborted illegally Compared to the rate in countries where abortion is legal at 69 19 Of pregnancies in 2012 120 million occurred in Asia 54 million in Africa 19 million in Europe 18 million in Latin America and the Caribbean 7 million in North America and 1 million in Oceania 11 Pregnancy rates are 140 per 1000 women of childbearing age in the developing world and 94 per 1000 in the developed world 11 The rate of pregnancy as well as the ages at which it occurs differ by country and region It is influenced by a number of factors such as cultural social and religious norms access to contraception and rates of education The total fertility rate TFR in 2013 was estimated to be highest in Niger 7 03 children woman and lowest in Singapore 0 79 children woman 159 In Europe the average childbearing age has been rising continuously for some time In Western Northern and Southern Europe first time mothers are on average 26 to 29 years old up from 23 to 25 years at the start of the 1970s In a number of European countries Spain the mean age of women at first childbirth has crossed the 30 year threshold This process is not restricted to Europe Asia Japan and the United States are all seeing average age at first birth on the rise and increasingly the process is spreading to countries in the developing world like China Turkey and Iran In the US the average age of first childbirth was 25 4 in 2010 160 In the United States and United Kingdom 40 of pregnancies are unplanned and between a quarter and half of those unplanned pregnancies were unwanted pregnancies 161 162 In the US a woman s educational attainment and her marital status are correlated with childbearing the percentage of women unmarried at the time of first birth drops with increasing educational level In other words among uneducated women a large fraction 80 have their first child while they are unmarried By contrast few women with a bachelor s degree or higher 25 have their first child while unmarried However this phenomenon also has a strong generational component in 1996 about 50 of women without a university degree had their first child being unmarried while that number increased to 85 in 2018 Similarly in 1996 only 4 of women with a BA degree or similar had their first child being unmarried In 2018 that fraction increased to 25 163 Legal and social aspectsLegal protection Further information Reproductive rights and Reproductive justice Many countries have various legal regulations in place to protect pregnant women and their children Many countries have laws against pregnancy discrimination 164 Maternity Protection Convention ensures that pregnant women are exempt from activities such as night shifts or carrying heavy stocks Maternity leave typically provides paid leave from work during roughly the last trimester of pregnancy and for some time after birth Notable extreme cases include Norway 8 months with full pay and the United States no paid leave at all except in some states In the United States some actions that result in miscarriage or stillbirth such as beating a pregnant woman are considered crimes One law that does so is the federal Unborn Victims of Violence Act In 2014 the American state of Tennessee passed a law which allows prosecutors to charge a woman with criminal assault if she uses illegal drugs during her pregnancy and her fetus or newborn is harmed as a result 165 However protections are not universal In Singapore the Employment of Foreign Manpower Act forbids current and former work permit holders from becoming pregnant or giving birth in Singapore without prior permission 166 167 Violation of the Act is punishable by a fine of up to S 10 000 US 7300 and deportation 166 168 and until 2010 their employers would lose their 5 000 security bond 169 Teenage pregnancy Main article Teenage pregnancy Teenage pregnancy is also known as adolescent pregnancy 170 The WHO defines adolescence as the period between the ages of 10 and 19 years 171 Adolescents face higher health risks than women who give birth at age 20 to 24 and their infants are at a higher risk for preterm birth low birth weight and other severe neonatal conditions Their children continue to face greater challenges both behavioral and physical throughout their lives Teenage pregnancies are also related to social issues including social stigma lower educational levels and poverty 172 173 170 Studies show that female adolescents are often in abusive relationships at the time of their conceiving 174 Nurse Family Partnership NFP is a non profit organization operating in the United States and the UK designed to serve the needs of low income young mothers who may have special needs in their first pregnancy Each mother served is partnered with a registered nurse early in her pregnancy and receives ongoing nurse home visits that continue through her child s second birthday NFP intervention has been associated with improvements in maternal health child health and economic security 175 176 Racial disparities There are significant racial imbalances in pregnancy and neonatal care systems 177 Midwifery guidance treatment and care have been related to better birth outcomes Diminishing racial inequities in health is an increasingly large public health challenge in the United States Despite the fact that average rates have decreased data on neonatal mortality demonstrates that racial disparities have persisted and grown The death rate for African American babies is nearly double that of white neonates According to studies congenital defects SIDS preterm birth and low birth weight are all more common among African American babies 178 Midwifery care has been linked to better birth and postpartum outcomes for both mother and child It caters to the needs of the woman and provides competent sympathetic care and is essential for maternal health improvement The presence of a doula or birth assistant during labor and delivery has also been associated with improved levels of satisfaction with medical birth care Providers recognized their profession from a historical standpoint a link to African origins the diaspora and prevailing African American struggles Providers participated in both direct clinical experience and activist involvement Advocacy efforts aimed to enhance the number of minority birth attendants and to promote the benefits of woman centered birth care to neglected areas 178 Transgender people Main article Transgender pregnancy Transgender people have experienced significant advances in societal acceptance in recent years leaving many health professionals unprepared to provide quality care A 2015 report suggests that numbers of transgender individuals who are seeking family planning fertility and pregnancy services could certainly be quite large Regardless of prior hormone replacement therapy treatments the progression of pregnancy and birthing procedures for transgender people who carry pregnancies are typically the same as those of cisgender women 179 however they may be subjected to discrimination which can include a variety of negative social emotional and medical experiences as pregnancy is regarded as an exclusively female activity According to a study by the American College of Obstetricians and Gynecologists there is a lack of awareness services and medical assistance available to pregnant trans men 180 Culture The Visitation Mary pregnant with Jesus visiting pregnant Elizabeth depicted as a statue at the Church of the Visitation in Ein Karem Israel In most cultures pregnant women have a special status in society and receive particularly gentle care 181 At the same time they are subject to expectations that may exert great psychological pressure such as having to produce a son and heir In many traditional societies pregnancy must be preceded by marriage on pain of ostracism of mother and illegitimate child Overall pregnancy is accompanied by numerous customs that are often subject to ethnological research often rooted in traditional medicine or religion The baby shower is an example of a modern custom Pregnancy is an important topic in sociology of the family The prospective child may preliminarily be placed into numerous social roles The parents relationship and the relation between parents and their surroundings are also affected A belly cast may be made during pregnancy as a keepsake Arts Main article Pregnancy in art Images of pregnant women especially small figurines were made in traditional cultures in many places and periods though it is rarely one of the most common types of image These include ceramic figures from some Pre Columbian cultures and a few figures from most of the ancient Mediterranean cultures Many of these seem to be connected with fertility Identifying whether such figures are actually meant to show pregnancy is often a problem as well as understanding their role in the culture concerned Among the oldest surviving examples of the depiction of pregnancy are prehistoric figurines found across much of Eurasia and collectively known as Venus figurines Some of these appear to be pregnant Due to the important role of the Mother of God in Christianity the Western visual arts have a long tradition of depictions of pregnancy especially in the biblical scene of the Visitation and devotional images called a Madonna del Parto 182 The unhappy scene usually called Diana and Callisto showing the moment of discovery of Callisto s forbidden pregnancy is sometimes painted from the Renaissance onwards Gradually portraits of pregnant women began to appear with a particular fashion for pregnancy portraits in elite portraiture of the years around 1600 Pregnancy and especially pregnancy of unmarried women is also an important motif in literature Notable examples include Thomas Hardy s 1891 novel Tess of the d Urbervilles and Goethe s 1808 play Faust See alsoCouvade syndrome Cryptic pregnancy False pregnancy Simulated pregnancyReferences a b What are some common signs of pregnancy Eunice Kennedy Shriver National Institute of Child Health and Human Development 12 July 2013 Archived from the original on 19 March 2015 Retrieved 14 March 2015 a b c The Johns Hopkins Manual of Gynecology and Obstetrics 4 ed Lippincott Williams amp Wilkins 2012 p 438 ISBN 978 1 4511 4801 5 Archived from the original on 10 September 2017 a b What are some common complications of pregnancy Eunice Kennedy Shriver National Institute of Child Health and Human Development 12 July 2013 Archived from the original on 26 February 2015 Retrieved 14 March 2015 a b c d e f g h i j k Pregnancy Condition Information Eunice Kennedy Shriver National Institute of Child Health and Human Development 19 December 2013 Archived from the original on 19 March 2015 Retrieved 14 March 2015 a b c d Abman SH 2011 Fetal and neonatal physiology 4th ed Philadelphia Elsevier Saunders pp 46 47 ISBN 978 1 4160 3479 7 a b Shehan CL 2016 The Wiley Blackwell Encyclopedia of Family Studies 4 Volume Set John Wiley amp Sons p 406 ISBN 978 0 470 65845 1 Archived from the original on 10 September 2017 a b How do I know if I m pregnant Eunice Kennedy Shriver National Institute of Child Health and Human Development 30 November 2012 Archived from the original on 2 April 2015 Retrieved 14 March 2015 a b Taylor D James EA 2011 An evidence based guideline for unintended pregnancy prevention Journal of Obstetric Gynecologic and Neonatal Nursing 40 6 782 793 doi 10 1111 j 1552 6909 2011 01296 x PMC 3266470 PMID 22092349 a b c d What is prenatal care and why is it important Eunice Kennedy Shriver National Institute of Child Health and Human Development 12 July 2013 Archived from the original on 2 April 2015 Retrieved 14 March 2015 Keats EC Haider BA Tam E Bhutta ZA March 2019 Multiple micronutrient supplementation for women during pregnancy The Cochrane Database of Systematic Reviews 3 3 CD004905 doi 10 1002 14651858 CD004905 pub6 PMC 6418471 PMID 30873598 a b c d e f g Sedgh G Singh S Hussain R September 2014 Intended and unintended pregnancies worldwide in 2012 and recent trends Studies in Family Planning 45 3 301 314 doi 10 1111 j 1728 4465 2014 00393 x PMC 4727534 PMID 25207494 a b c d e Naghavi Mohsen et al GBD 2016 Causes of Death Collaborators September 2017 Global regional and national age sex specific mortality for 264 causes of death 1980 2016 a systematic analysis for the Global Burden of Disease Study 2016 Lancet 390 10100 1151 1210 doi 10 1016 S0140 6736 17 32152 9 PMC 5605883 PMID 28919116 a b Mosby 2009 Mosby s Pocket Dictionary of Medicine Nursing amp Health Professions E Book Elsevier Health Sciences p 1078 ISBN 978 0323066044 Wylie L 2005 Essential anatomy and physiology in maternity care Second ed Edinburgh Churchill Livingstone p 172 ISBN 978 0 443 10041 3 Archived from the original on 10 September 2017 Massachusetts General Laws c 112 12K Definitions applicable to Secs 12L to 12U Commonwealth of Massachusetts 2022 a b c d e Lammi Keefe CJ Couch SC Philipson EH eds 2008 Handbook of Nutrition and Pregnancy Nutrition and health Totowa NJ Humana Press p 28 doi 10 1007 978 1 59745 112 3 ISBN 978 1 59745 112 3 a b c d American Congress of Obstetricians and Gynecologists February 2013 Five Things Physicians and Patients Should Question Choosing Wisely an initiative of the ABIM Foundation American Congress of Obstetricians and Gynecologists archived from the original on 1 September 2013 retrieved 1 August 2013 World Health Organization November 2014 Preterm birth Fact sheet N 363 who int Archived from the original on 7 March 2015 Retrieved 6 March 2015 a b c Bearak J Popinchalk A Alkema L Sedgh G April 2018 Global regional and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014 estimates from a Bayesian hierarchical model The Lancet Global Health 6 4 e380 e389 doi 10 1016 S2214 109X 18 30029 9 PMC 6055480 PMID 29519649 Hurt KJ Guile MW Bienstock JL Fox HE Wallach EE 28 March 2012 The Johns Hopkins manual of gynecology and obstetrics 4th ed Philadelphia Wolters Kluwer Health Lippincott Williams amp Wilkins p 382 ISBN 978 1 60547 433 5 a b definition of gravida The Free Dictionary Retrieved 17 January 2008 Gravidity and Parity Definitions Implications in Risk Assessment patient info Archived from the original on 12 December 2016 Robinson Victor ed 1939 Primipara The Modern Home Physician A New Encyclopedia of Medical Knowledge WM H Wise amp Company New York page 596 Definition of nulligravida Merriam Webster Incorporated Archived from the original on 8 September 2008 Retrieved 9 March 2012 Nulliparous definition MedicineNet Inc 18 November 2000 Archived from the original on 9 July 2009 Definition of Term Pregnancy ACOG www acog org Retrieved 27 September 2019 Definition of Premature birth Medicine net Archived from the original on 9 July 2009 Retrieved 16 January 2008 Lama Rimawi MD 22 September 2006 Premature Infant Disease amp Conditions Encyclopedia Discovery Communications LLC Archived from the original on 19 January 2008 Retrieved 16 January 2008 Merck Urinary tract infections during pregnancy Merck Manual Home Health Handbook Archived from the original on 10 November 2011 Vazquez JC August 2010 Constipation haemorrhoids and heartburn in pregnancy BMJ Clinical Evidence 2010 1411 PMC 3217736 PMID 21418682 MedlinePlus gt Breast pain Archived 5 August 2012 at archive today Update Date 31 December 2008 Updated by David C Dugdale Susan Storck Also reviewed by David Zieve a b c d e f g h i j Nair M Kumar B 7 April 2016 Embryology for fetal medicine In Kumar B Alfirevic Z eds Fetal Medicine Cambridge University Press pp 54 59 ISBN 978 1 107 06434 8 a b c d Mishra S ed 7 August 2019 Langman s Medical Embryology Wolters kluwer india Pvt Ltd p 48 ISBN 978 93 88696 53 1 a b Obstetric Data Definitions Issues and Rationale for Change Gestational Age amp Term Archived 6 November 2013 at the Wayback Machine from Patient Safety and Quality Improvement at American Congress of Obstetricians and Gynecologists Created November 2012 Tunon K Eik Nes SH Grottum P Von During V Kahn JA January 2000 Gestational age in pregnancies conceived after in vitro fertilization a comparison between age assessed from oocyte retrieval crown rump length and biparietal diameter Ultrasound in Obstetrics amp Gynecology 15 1 41 46 doi 10 1046 j 1469 0705 2000 00004 x PMID 10776011 S2CID 20029116 a b c d Pregnancy the three trimesters University of California San Francisco Retrieved 30 November 2019 a b Hoffman CS Messer LC Mendola P Savitz DA Herring AH Hartmann KE November 2008 Comparison of gestational age at birth based on last menstrual period and ultrasound during the first trimester Paediatric and Perinatal Epidemiology 22 6 587 596 doi 10 1111 j 1365 3016 2008 00965 x PMID 19000297 Calculating Your Due Date Healthline Networks Inc Archived from the original on 21 December 2009 Retrieved 13 January 2010 ement Health IT and Clinical Informatics reVITALize Obstetrics Data Definitions reVITALize Obstetrics Data Definitions ACOG Retrieved 27 November 2022 Chambliss LR Clark SL February 2014 Paper gestational age wheels are generally inaccurate American Journal of Obstetrics and Gynecology 210 2 145 e1 145 e4 doi 10 1016 j ajog 2013 09 013 PMID 24036402 Zegers Hochschild F Adamson GD Dyer S Racowsky C de Mouzon J Sokol R et al September 2017 The International Glossary on Infertility and Fertility Care 2017 Fertility and Sterility Elsevier BV 108 3 393 406 doi 10 1016 j fertnstert 2017 06 005 PMID 28760517 S2CID 3640374 Differences in sex development nhs uk 18 November 2021 Retrieved 29 June 2022 Weschler T 2002 Taking Charge of Your Fertility Revised ed New York HarperCollins pp 242 374 ISBN 978 0 06 093764 5 Berger KS 2011 The Developing Person Through the Life Span Macmillan p 90 ISBN 978 1 4292 3205 0 Archived from the original on 25 April 2016 Stages of Development of the Fetus Women s Health Issues MSD Manual Consumer Version Retrieved 10 July 2020 Lennart Nilsson A Child is Born 91 1990 at eight weeks the danger of a miscarriage diminishes sharply Women s Health Information Archived 30 April 2007 at the Wayback Machine Hearthstone Communications Limited The risk of miscarriage decreases dramatically after the 8th week as the weeks go by Retrieved 2007 04 22 Kalverboer AF Gramsbergen AA 1 January 2001 Handbook of Brain and Behaviour in Human Development Springer p 1 ISBN 978 0 7923 6943 1 Archived from the original on 19 September 2015 Illes J ed 2008 Neuroethics defining the issues in theory practice and policy Repr ed Oxford Oxford University Press p 142 ISBN 978 0 19 856721 9 Archived from the original on 19 September 2015 Harley TA 2021 The Science of Consciousness Waking Sleeping and Dreaming Cambridge United Kingdom Cambridge University Press p 245 ISBN 978 1 107 12528 5 Retrieved 3 May 2022 Cleeremans A Wilken P Bayne T eds 2009 The Oxford Companion to Consciousness New York NY Oxford University Press p 229 ISBN 978 0 19 856951 0 Retrieved 3 May 2022 Thompson E Moscovitch M Zelazo PD eds 2007 The Cambridge Handbook of Consciousness Cambridge United Kingdom Cambridge University Press pp 415 417 ISBN 9781139464062 Retrieved 3 May 2022 Abortion amp Pregnancy Risks Louisiana Department of Health Retrieved 22 August 2019 Reproductive History and Cancer Risk National Cancer Institute 30 November 2016 Retrieved 23 August 2019 a b Mor G ed 2006 Immunology of pregnancy Medical intelligence unit Georgetown Tex New York Landes Bioscience Eurekah com Springer Science Business Media pp 1 4 doi 10 1007 0 387 34944 8 ISBN 978 0 387 34944 2 Williams Z September 2012 Inducing tolerance to pregnancy The New England Journal of Medicine 367 12 1159 1161 doi 10 1056 NEJMcibr1207279 PMC 3644969 PMID 22992082 Campbell LA Klocke RA April 2001 Implications for the pregnant patient American Journal of Respiratory and Critical Care Medicine 163 5 1051 1054 doi 10 1164 ajrccm 163 5 16353 PMID 11316633 Your baby at 0 8 weeks pregnancy Pregnancy and baby guide NHS Choices nhs uk 20 December 2017 Archived from the original on 20 November 2013 Hennen L Murray L Scott J 2005 The BabyCenter Essential Guide to Pregnancy and Birth Expert Advice and Real World Wisdom from THE tip Top Pregnancy and Parenting Resource Emmaus Penn Rodale Books ISBN 1 59486 211 7 Pregnancy Dropping Lightening University of Michigan Retrieved 9 June 2021 Stacey T Thompson JM Mitchell EA Ekeroma AJ Zuccollo JM McCowan LM June 2011 Association between maternal sleep practices and risk of late stillbirth a case control study BMJ 342 d3403 doi 10 1136 bmj d3403 PMC 3114953 PMID 21673002 a b c d e f g h i j k Cunningham FG Leveno KJ Bloom SL Spong CY Dashe JS Hoffman BL Casey BM Sheffield JS eds 2014 Chapter 12 Teratology Teratogens and Fetotoxic Agents William s Obstetrics McGraw Hill Education ISBN 978 0 07 179893 8 Archived from the original on 31 December 2018 Retrieved 9 November 2015 RHL apps who int Archived from the original on 27 December 2011 a b World Health Organization November 2013 Preterm birth who int Archived from the original on 7 September 2014 Retrieved 19 September 2014 a b c d e f g h American Congress of Obstetricians and Gynecologists Society for Maternal Fetal Medicine 22 October 2013 Ob Gyns Redefine Meaning of Term Pregnancy acog org Archived from the original on 15 September 2014 Retrieved 19 September 2014 Saigal S Doyle LW January 2008 An overview of mortality and sequelae of preterm birth from infancy to adulthood Lancet 371 9608 261 269 doi 10 1016 S0140 6736 08 60136 1 PMID 18207020 S2CID 17256481 American Congress of Obstetricians and Gynecologists February 2013 Five Things Physicians and Patients Should Question Choosing Wisely an initiative of the ABIM Foundation American Congress of Obstetricians and Gynecologists archived from the original on 1 September 2013 retrieved 1 August 2013 which cites Main E Oshiro B Chagolla B Bingham D Dang Kilduff L Kowalewski L Elimination of Non medically Indicated Elective Deliveries Before 39 Weeks Gestational Age PDF March of Dimes California Maternal Quality Care Collaborative Maternal Child and Adolescent Health Division Center for Family Health California Department of Public Health archived from the original PDF on 10 November 2012 retrieved 1 August 2013 Michele Norris 18 July 2011 Doctors To Pregnant Women Wait at Least 39 Weeks All Things Considered Archived from the original on 23 July 2011 Retrieved 20 August 2011 Norwitz ER Postterm Pregnancy Beyond the Basics UpToDate Inc Archived from the original on 7 October 2012 Retrieved 24 August 2012 The American College of Obstetricians and Gynecologists April 2006 What To Expect After Your Due Date Medem Medem Inc Archived from the original on 29 April 2003 Retrieved 16 January 2008 Induction of labour Evidence based Clinical Guideline Number 9 PDF Royal College of Obstetricians and Gynaecologists 2001 Archived from the original PDF on 30 December 2006 Retrieved 18 January 2008 Jenkins A Millar S Robins J July 2011 Denial of pregnancy a literature review and discussion of ethical and legal issues Journal of the Royal Society of Medicine 104 7 286 291 doi 10 1258 jrsm 2011 100376 PMC 3128877 PMID 21725094 Gabbe S 1 January 2012 Obstetrics normal and problem pregnancies 6th ed Philadelphia Elsevier Saunders p 1184 ISBN 978 1 4377 1935 2 Pregnancy Symptoms National Health Service NHS 11 March 2010 Archived from the original on 28 February 2010 Retrieved 11 March 2010 a b Early symptoms of pregnancy What happens right away Mayo Clinic 22 February 2007 Archived from the original on 14 September 2007 Retrieved 22 August 2007 a b Pregnancy Symptoms Early Signs of Pregnancy American Pregnancy Association Archived from the original on 15 January 2008 Retrieved 16 January 2008 Pregnancy video Channel 4 2008 Archived from the original on 23 January 2009 Retrieved 22 January 2009 NHS Pregnancy Planner National Health Service NHS 19 March 2010 Retrieved 19 March 2010 Cole LA Butler SA eds 2015 Human chorionic gonadotropin hCG 2nd ed Amsterdam Elsevier ISBN 978 0 12 800821 8 Archived from the original on 26 January 2021 Retrieved 10 November 2015 Qasim SM Callan C Choe JK October 1996 The predictive value of an initial serum beta human chorionic gonadotropin level for pregnancy outcome following in vitro fertilization Journal of Assisted Reproduction and Genetics 13 9 705 708 doi 10 1007 BF02066422 PMID 8947817 S2CID 36218409 BestBets Serum or Urine beta hCG Archived from the original on 31 December 2008 a b Cole LA Khanlian SA Sutton JM Davies S Rayburn WF January 2004 Accuracy of home pregnancy tests at the time of missed menses American Journal of Obstetrics and Gynecology 190 1 100 105 doi 10 1016 j ajog 2003 08 043 PMID 14749643 Verhaegen J Gallos ID van Mello NM Abdel Aziz M Takwoingi Y Harb H et al September 2012 Accuracy of single progesterone test to predict early pregnancy outcome in women with pain or bleeding meta analysis of cohort studies BMJ 345 e6077 doi 10 1136 bmj e6077 PMC 3460254 PMID 23045257 Whitworth M Bricker L Mullan C July 2015 Ultrasound for fetal assessment in early pregnancy The Cochrane Database of Systematic Reviews 2015 7 CD007058 doi 10 1002 14651858 CD007058 pub3 PMC 4084925 PMID 26171896 Nguyen TH Larsen T Engholm G Moller H July 1999 Evaluation of ultrasound estimated date of delivery in 17 450 spontaneous singleton births do we need to modify Naegele s rule Ultrasound in Obstetrics amp Gynecology 14 1 23 28 doi 10 1046 j 1469 0705 1999 14010023 x PMID 10461334 S2CID 30749264 Pyeritz RE 2014 Current Medical Diagnosis amp Treatment 2015 McGraw Hill Waters TR MacDonald LA Hudock SD Goddard DE February 2014 Provisional recommended weight limits for manual lifting during pregnancy Human Factors 56 1 203 214 doi 10 1177 0018720813502223 PMC 4606868 PMID 24669554 Archived from the original on 1 April 2017 MacDonald LA Waters TR Napolitano PG Goddard DE Ryan MA Nielsen P Hudock SD August 2013 Clinical guidelines for occupational lifting in pregnancy evidence summary and provisional recommendations American Journal of Obstetrics and Gynecology 209 2 80 88 doi 10 1016 j ajog 2013 02 047 PMC 4552317 PMID 23467051 a b Lyons P 2015 Obstetrics in family medicine a practical guide Current clinical practice 2nd ed Cham Switzerland Humana Press pp 19 28 ISBN 978 3 319 20077 4 Archived from the original on 26 January 2021 Retrieved 11 November 2015 WHO Antenatal care www who int Archived from the original on 20 November 2015 Retrieved 10 November 2015 Dowswell T Carroli G Duley L Gates S Gulmezoglu AM Khan Neelofur D Piaggio G et al American College of Obstetricians Gynecologists Committee on Health Care for Undeserved Women July 2015 Alternative versus standard packages of antenatal care for low risk pregnancy The Cochrane Database of Systematic Reviews 2015 7 CD000934 doi 10 1002 14651858 cd000934 pub3 PMC 7061257 PMID 26184394 American College of Obstetricians Gynecologists Committee on Health Care for Undeserved Women August 2006 ACOG Committee Opinion No 343 psychosocial risk factors perinatal screening and intervention Obstetrics and Gynecology 108 2 469 477 doi 10 1097 00006250 200608000 00046 PMID 16880322 Hurt JK ed 2011 The Johns Hopkins manual of gynecology and obstetrics 4th ed Philadelphia Wolters Kluwer Health Lippincott Williams amp Wilkins ISBN 978 1 4511 0913 9 McCormick MC Siegel JE eds 1999 Prenatal care effectiveness and implementation Cambridge UK New York Cambridge University Press ISBN 978 0 521 66196 6 Archived from the original on 6 November 2018 Retrieved 10 November 2015 Ota E Hori H Mori R Tobe Gai R Farrar D June 2015 Antenatal dietary education and supplementation to increase energy and protein intake The Cochrane Database of Systematic Reviews 2015 6 CD000032 doi 10 1002 14651858 CD000032 pub3 PMID 26031211 Choose MyPlate Choose MyPlate 29 April 2015 Archived from the original on 17 November 2015 Retrieved 15 November 2015 Tieu J Shepherd E Middleton P Crowther CA January 2017 Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus The Cochrane Database of Systematic Reviews 1 1 CD006674 doi 10 1002 14651858 CD006674 pub3 PMC 6464792 PMID 28046205 Klusmann A Heinrich B Stopler H Gartner J Mayatepek E Von Kries R November 2005 A decreasing rate of neural tube defects following the recommendations for periconceptional folic acid supplementation Acta Paediatrica 94 11 1538 1542 doi 10 1080 08035250500340396 PMID 16303691 S2CID 13506877 Stevenson RE Allen WP Pai GS Best R Seaver LH Dean J Thompson S October 2000 Decline in prevalence of neural tube defects in a high risk region of the United States Pediatrics 106 4 677 683 doi 10 1542 peds 106 4 677 PMID 11015508 S2CID 39696556 Folic acid in diet MedlinePlus Medical Encyclopedia www nlm nih gov Archived from the original on 17 November 2015 Retrieved 15 November 2015 Centers for Disease Control Prevention CDC January 2008 Use of supplements containing folic acid among women of childbearing age United States 2007 MMWR Morbidity and Mortality Weekly Report 57 1 5 8 PMID 18185493 a b c Viswanathan M Siega Riz AM Moos MK et al May 2008 Outcomes of Maternal Weight Gain Evidence Reports Technology Assessments No 168 Agency for Healthcare Research and Quality pp 1 223 PMC 4781425 PMID 18620471 Archived from the original on 28 May 2013 Retrieved 23 June 2013 a b c Institute for Quality and Efficiency in Health Care Weight gain in pregnancy Fact sheet Institute for Quality and Efficiency in Health Care Archived from the original on 14 December 2013 Retrieved 23 June 2013 Weight Gain During Pregnancy Reexaminging the Guidelines Report Brief Institute of Medicine Archived from the original on 10 August 2010 Retrieved 29 July 2010 American College of Obstetricians Gynecologists January 2013 ACOG Committee opinion no 548 weight gain during pregnancy Obstetrics and Gynecology 121 1 210 212 doi 10 1097 01 AOG 0000425668 87506 4c PMID 23262962 a b c Thangaratinam S Rogozinska E Jolly K Glinkowski S Duda W Borowiack E et al July 2012 Interventions to reduce or prevent obesity in pregnant women a systematic review Health Technology Assessment National Institute for Health and Care Research 16 31 iii iv 1 191 doi 10 3310 hta16310 PMC 4781281 PMID 22814301 Bushnell C McCullough LD Awad IA Chireau MV Fedder WN Furie KL et al May 2014 Guidelines for the prevention of stroke in women a statement for healthcare professionals from the American Heart Association American Stroke Association Stroke 45 5 1545 1588 doi 10 1161 01 str 0000442009 06663 48 PMID 24503673 S2CID 6297484 a b c Briggs GG Freeman RK 2015 Drugs in pregnancy and lactation A Reference Guide to Fetal and Neonatal Risk Tenth ed Philadelphia Wolters Kluwer Lippincott Williams amp Wilkins Health p Appendix ISBN 978 1 4511 9082 3 Archived from the original on 25 February 2021 Retrieved 16 November 2015 Genetic Alliance The New England Public Health Genetics Education Collaborative 17 February 2010 Appendix A Teratogens Prenatal Substance Abuse Understanding Genetics A New England Guide for Patients and Health Professionals Genetic Alliance Press Announcements FDA issues final rule on changes to pregnancy and lactation labeling information for prescription drug and biological products www fda gov Archived from the original on 17 November 2015 Retrieved 16 November 2015 Basics about FASDs CDC Retrieved 25 July 2018 Hackshaw A Rodeck C Boniface S September October 2011 Maternal smoking in pregnancy and birth defects a systematic review based on 173 687 malformed cases and 11 7 million controls Human Reproduction Update 17 5 589 604 doi 10 1093 humupd dmr022 PMC 3156888 PMID 21747128 Centers for Disease Control and Prevention 2007 Preventing Smoking and Exposure to Secondhand Smoke Before During and After Pregnancy Archived 11 September 2011 at the Wayback Machine Tobacco Use and Pregnancy Reproductive Health www cdc gov 16 January 2019 Archived from the original on 29 July 2017 a b New Mother Fact Sheet Methamphetamine Use During Pregnancy North Dakota Department of Health Archived from the original on 10 September 2011 Retrieved 7 October 2011 Della Grotta S LaGasse LL Arria AM Derauf C Grant P Smith LM et al July 2010 Patterns of methamphetamine use during pregnancy results from the Infant Development Environment and Lifestyle IDEAL Study Maternal and Child Health Journal 14 4 519 527 doi 10 1007 s10995 009 0491 0 PMC 2895902 PMID 19565330 Martin R Dombrowski SC 2008 12 Air and Water Pollution Prenatal exposures psychological and educational consequences for children New York Springer doi 10 1007 978 0 387 74398 1 ISBN 978 0 387 74398 1 Byrne CC 2006 Environmental hazards during pregnancy Journal of Midwifery and Women s Health 1 51 57 58 doi 10 1016 j jmwh 2005 09 008 PMID 16402445 N95 Respirator Use During Pregnancy Findings from Recent NIOSH Research NIOSH Science Blog Blogs CDC blogs cdc gov Archived from the original on 16 November 2016 Retrieved 16 November 2016 Boston 677 Huntington Avenue Ma 02115 1495 1000 21 October 2022 Homicide leading cause of death for pregnant women in U S News Retrieved 8 November 2022 With homicide a leading cause of maternal death doctors urged to screen pregnant women for domestic violence CNN Health 20 October 2022 Retrieved 8 November 2022 Wallace Maeve E 2022 Trends in Pregnancy Associated Homicide United States 2020 American Journal of Public Health 112 9 1333 1336 doi 10 2105 AJPH 2022 306937 PMC 9382166 PMID 35797500 Retrieved 8 November 2022 a b c Cunningham FG Leveno KJ Bloom SL Spong CY Dashe JS Hoffman BL Casey BM Sheffield JS eds 2014 Chapter 9 Prenatal Care Williams Obstetrics 24th ed New York McGraw Hill Education ISBN 978 0 07 179893 8 Archived from the original on 31 December 2018 Retrieved 9 November 2015 Bermudez MP Sanchez AI Buela Casal G 2001 Influence of the Gestation Period on Sexual Desire Psychology in Spain 5 1 14 16 Archived from the original on 9 February 2012 Fok WY Chan LY Yuen PM October 2005 Sexual behavior and activity in Chinese pregnant women Acta Obstetricia et Gynecologica Scandinavica 84 10 934 938 doi 10 1111 j 0001 6349 2005 00743 x PMID 16167907 S2CID 23075166 Reamy K White SE Daniell WC Le Vine ES June 1982 Sexuality and pregnancy A prospective study The Journal of Reproductive Medicine 27 6 321 327 PMID 7120209 Malarewicz A Szymkiewicz J Rogala J September 2006 Sexuality of pregnant women Ginekologia Polska in Polish 77 9 733 739 PMID 17219804 Kramer MS McDonald SW July 2006 Kramer MS ed Aerobic exercise for women during pregnancy The Cochrane Database of Systematic Reviews 3 3 CD000180 doi 10 1002 14651858 CD000180 pub2 PMC 7043271 PMID 16855953 Domenjoz I Kayser B Boulvain M October 2014 Effect of physical activity during pregnancy on mode of delivery American Journal of Obstetrics and Gynecology 211 4 401 e1 401 11 doi 10 1016 j ajog 2014 03 030 PMID 24631706 a b Beetham KS Giles C Noetel M Clifton V Jones JC Naughton G August 2019 The effects of vigorous intensity exercise in the third trimester of pregnancy a systematic review and meta analysis BMC Pregnancy and Childbirth 19 1 281 doi 10 1186 s12884 019 2441 1 PMC 6686535 PMID 31391016 Di Mascio D Magro Malosso ER Saccone G Marhefka GD Berghella V November 2016 Exercise during pregnancy in normal weight women and risk of preterm birth a systematic review and meta analysis of randomized controlled trials American Journal of Obstetrics and Gynecology 215 5 561 571 doi 10 1016 j ajog 2016 06 014 hdl 11573 1110770 PMID 27319364 S2CID 32419788 McCall CA Grimes DA Lyerly AD June 2013 Therapeutic bed rest in pregnancy unethical and unsupported by data Obstetrics and Gynecology 121 6 1305 1308 doi 10 1097 aog 0b013e318293f12f PMID 23812466 Davies GA Wolfe LA Mottola MF MacKinnon C Arsenault MY Bartellas E et al June 2003 Exercise in pregnancy and the postpartum period Journal of Obstetrics and Gynaecology Canada 25 6 516 529 doi 10 1016 s1701 2163 16 30313 9 PMID 12806453 a b c Artal R O Toole M February 2003 Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period British Journal of Sports Medicine 37 1 6 12 discussion 12 doi 10 1136 bjsm 37 1 6 PMC 1724598 PMID 12547738 Reiter RJ Tan DX Korkmaz A Rosales Corral SA 2014 Melatonin and stable circadian rhythms optimize maternal placental and fetal physiology Human Reproduction Update 20 2 293 307 doi 10 1093 humupd dmt054 PMID 24132226 Oral health care during pregnancy A strategies and considerations PDF Archived from the original PDF on 22 August 2018 Retrieved 2 June 2018 Jafarzadeh H Sanatkhani M Mohtasham N December 2006 Oral pyogenic granuloma a review Journal of Oral Science 48 4 167 175 doi 10 2334 josnusd 48 167 PMID 17220613 Iheozor Ejiofor Z Middleton P Esposito M Glenny AM June 2017 Treating periodontal disease for preventing adverse birth outcomes in pregnant women The Cochrane Database of Systematic Reviews 2017 6 CD005297 doi 10 1002 14651858 CD005297 pub3 PMC 6481493 PMID 28605006 Howland G 2017 The Mama Natural Week by Week Guide to Pregnancy and Childbirth Simon and Schuster p 173 ISBN 9781501146688 a b c Jarvis S Stone J Eddleman K Duenwald M 2011 Pregnancy For Dummies John Wiley amp Sons p 157 ISBN 9781119997061 TSA Travel Tips for Pregnant Passengers Transportation Security Administration 22 July 2014 Archived from the original on 6 August 2020 Retrieved 27 February 2019 Antenatal classes NHS December 2020 Retrieved 16 November 2022 Promoting baby friendly hospitals World Health Organization Retrieved 16 November 2022 Reproductive Health and Research Publications Making Pregnancy Safer World Health Organization Regional Office for South East Asia 2009 Archived from the original on 15 December 2009 Retrieved 7 December 2009 Pregnancy complicated by disease Merck Manual Home Health Handbook Merck Sharp amp Dohme Stewart DE Vigod S December 2016 Postpartum Depression The New England Journal of Medicine 375 22 2177 2186 doi 10 1056 nejmcp1607649 PMID 27959754 Lara A Friel Thromboembolic Disorders During Pregnancy Merck Sharp amp Dohme Corp a b Leveno K 2013 52 Williams Manual of Pregnancy Complications New York McGraw Hill Medical pp 323 334 ISBN 978 0 07 176562 6 What are the symptoms of pregnancy loss before 20 weeks of pregnancy NIH Retrieved 4 October 2022 Miscarriage Causes WebMD Retrieved 6 October 2022 What Is Stillborn CDC 29 September 2022 Retrieved 6 October 2022 Miscarriage NHS a href Template Cite web html title Template Cite web cite web a Missing or empty url help Obst K L Due C Oxlad M Middleton P 2020 Men s grief following pregnancy loss and neonatal loss a systematic review and emerging theoretical model BMC Pregnancy and Childbirth 20 1 11 doi 10 1186 s12884 019 2677 9 PMC 6953275 PMID 31918681 Tersigni C Castellani R de Waure C Fattorossi A De Spirito M Gasbarrini A et al 2014 Celiac disease and reproductive disorders meta analysis of epidemiologic associations and potential pathogenic mechanisms Human Reproduction Update 20 4 582 593 doi 10 1093 humupd dmu007 PMID 24619876 Saccone G Berghella V Sarno L Maruotti GM Cetin I Greco L et al February 2016 Celiac disease and obstetric complications a systematic review and metaanalysis American Journal of Obstetrics and Gynecology 214 2 225 234 doi 10 1016 j ajog 2015 09 080 PMID 26432464 The Gluten Connection Health Canada May 2009 Archived from the original on 5 July 2017 Retrieved 1 October 2013 a b Page 264 in Gresele Paolo 2008 Platelets in hematologic and cardiovascular disorders a clinical handbook Cambridge UK Cambridge University Press ISBN 978 0 521 88115 9 Zdanowicz C 21 May 2019 Women have abortions for many reasons aside from rape and incest Here are some of them CNN Retrieved 2 July 2022 Law and Policy Guide Rape and Incest Exceptions Center for Reproductive Rights 18 January 2022 Retrieved 2 July 2022 SDG Indicator 3 7 1 on Contraceptive Use Population Division Retrieved 3 July 2022 a b c Guidelines for Diagnostic Imaging During Pregnancy and Lactation American Congress of Obstetricians and Gynecologists Archived from the original on 30 July 2017 February 2016 The World Factbook cia gov Archived from the original on 28 October 2009 National Vital Statistics Reports Archived 20 July 2017 at the Wayback Machine from Centers for Disease Control and Prevention National Center for Health Statistics Volume 61 Number 1 August 28 2012 Births Final Data for 2010 40 of pregnancies unplanned BBC News 16 March 2004 Archived from the original on 30 July 2012 Jayson S 20 May 2011 Unplanned pregnancies in U S at 40 percent PhysOrg com Archived from the original on 5 January 2012 Cherlin AJ September 2021 Rising nonmarital first childbearing among college educated women Evidence from three national studies Proceedings of the National Academy of Sciences of the United States of America 118 37 e2109016118 Bibcode 2021PNAS 11809016C doi 10 1073 pnas 2109016118 PMC 8449381 PMID 34493673 Maternity and paternity at work Law and practice across the world International Labour Organization Retrieved 3 September 2022 Katie Mcdonough 30 April 2014 Tennessee just became the first state that will jail women for their pregnancy outcomes Salon Archived from the original on 5 May 2014 Retrieved 5 May 2014 a b NONFICTION When Pregnancy is a Crime 17 June 2021 Employment of Foreign Manpower Work Passes Regulations 2012 Singapore Statutes Online Employment of Foreign Manpower Act Singapore Statutes Online Employers will not lose security bond if FDW gets pregnant MOM twc2 org sg 1 July 2011 Retrieved 15 December 2021 a b Adolescent pregnancy World Health Organization Retrieved 26 October 2022 Adolescent health www who int What Are the Effects of Teenage Pregnancy Healthline 19 September 2016 Retrieved 26 October 2022 The Adverse Effects of Teen Pregnancy youth gov Retrieved 26 October 2022 Bekaert S Smithbattle L 2016 Teen Mothers Experience of Intimate Partner Violence A Metasynthesis Ans Advances in Nursing Science 39 3 272 290 doi 10 1097 ANS 0000000000000129 PMID 27490882 S2CID 10471475 Retrieved 26 October 2022 Nurse Family Partnership Social Programs that Work Retrieved 4 December 2022 Miller Claire Cain 25 July 2017 How Home Visits by Nurses Help Mothers and Children Especially Boys The New York Times Retrieved 6 December 2022 Pereira GM Pimentel VM Surita FG Silva AD Brito LG 2022 Perceived racism or racial discrimination and the risk of adverse obstetric outcomes a systematic review Sao Paulo Med J 140 5 705 718 doi 10 1590 1516 3180 2021 0505 R1 07042022 PMC 9514866 PMID 36043663 a b Guerra Reyes L Hamilton LJ February 2017 Racial disparities in birth care Exploring the perceived role of African American women providing midwifery care and birth support in the United States Women and Birth 30 1 e9 e16 doi 10 1016 j wombi 2016 06 004 PMID 27364419 Obedin Maliver Juno Makadon Harvey J 2016 Transgender men and pregnancy Obstetric Medicine 9 1 4 8 doi 10 1177 1753495X15612658 PMC 4790470 PMID 27030799 Light AD Obedin Maliver J Sevelius JM Kerns JL December 2014 Transgender men who experienced pregnancy after female to male gender transitioning Obstetrics and Gynecology 124 6 1120 1127 doi 10 1097 AOG 0000000000000540 PMID 25415163 S2CID 36023275 Womack M 2010 The anthropology of health and healing Plymouth AltaMira Press p 133 ISBN 978 0 7591 1044 1 Rossi TV 2005 Mary in western art New York In Association with Hudson Hills Press p 106 ISBN 978 0 9712981 9 4 Further reading Nutrition for the First Trimester of Pregnancy IDEA Health amp Fitness Association Retrieved 9 December 2013 Bothwell TH July 2000 Iron requirements in pregnancy and strategies to meet them The American Journal of Clinical Nutrition 72 1 Suppl 257S 264S doi 10 1093 ajcn 72 1 257S PMID 10871591 Stevens J June 2005 Pregnancy envy and the politics of compensatory masculinities Politics amp Gender 1 2 265 296 CiteSeerX 10 1 1 485 5791 doi 10 1017 S1743923X05050087 S2CID 39231847 External links Wikimedia Commons has media related to Human pregnancy Wikiquote has quotations related to Pregnancy Pregnancy at Curlie Merck Manual Home Health Handbook further details on the diseases disorders etc which may complicate pregnancy Pregnancy care NHS guide to having a baby including preconception pregnancy labor and birth Retrieved from https en wikipedia org w index php title Pregnancy amp oldid 1145565306, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.