A Healthy Pregnancy

Initial Prenatal Visit

The initial prenatal visit should include a detailed history, including the history of the current pregnancy, a general past medical and surgical history, an OB history, and a GYN history.

With regard to the current pregnancy, be sure to ask about:

  • Last menstrual period

  • Other dating information (IUI or IVF dates, early ultrasound, etc)

  • Nausea and vomiting ("morning sickness")

  • Bleeding or spotting

  • Cramping

Particularly important aspects of the general history include:

  • Surgeries, especially in the abdomen or pelvis

  • Medications

  • Allergies

  • Other medical conditions

The OB history should include:

  • Gs and Ps (number, dates, and outcomes of prior pregnancies - term vaginal delivery, c-section, etc)

  • Personal or family history of mental retardation or congenital defects

  • History of 3rd or 4th degree tears

​The GYN history should include, at a minimum:

  • Age at menarche

  • Age at coitarche (first sexual intercourse)

  • Prior STDs

  • Pap history - If abnormal, how were they treated?

If it has not already been performed, a dating ultrasound should be scheduled as soon as possible, and before 14 weeks' gestational age.

Screening labs during the initial prenatal visit include:

  • Pap smear (if not already up to date)

  • Urinalysis and urine culture

  • Complete blood count

  • ABO and Rh type, blood antibody screen

  • Gonorrhea (if indicated) and chlamydia screening

  • RPR or VDRL for syphilis

  • Rubella antibody titer

  • Hepatitis B surface antigen

  • HIV screening (requires consent)

  • Varicella titer (if there is no clear history of chicken pox or varicella vaccination)

Physiological Changes in Pregnancy

Cardio

Cardiovascular changes that occur during pregnancy include an increase in cardiac output and a decrease in blood pressure, both of which improve uteroplacental perfusion.

Typically, systolic blood pressure decreases by 5-10 mmHg and diastolic blood pressure decreases by 10-15 mmHg during pregnancy.

Respiratory

Respiratory changes that occur during pregnancy include an increase in:

  • Tidal volume

  • Minute ventilation

  • Alveolar and arterial PO2

During pregnancy, there is a decrease in alveolar and arterial PCO2. The decrease in CO2 levels increases the CO2 gradient between the mother and fetus, which improves oxygen delivery to the fetus and CO2 removal.

As many as 70% of patients experience dyspnea during pregnancy.

Maternal asthma, as a result of preexisting asthma, is associated with severe maternal complications such as:

  • Preeclampsia

  • Spontaneous abortion

  • Intrauterine fetal demise

  • Intrauterine growth restriction

  • Increased risk of preterm delivery

During pregnancy, 1/3 of patients will see an improvement in their asthma, 1/3 will stay the same, and 1/3 will get worse. Because of the respiratory changes that occur during pregnancy, the mother may not tolerate exacerbations as well.

Renal

Renal changes that occur during pregnancy include an increase in renal blood flow, increased renal size, and ureteral dilation.

The GFR (glomerular filtration rate) increases by 50% during pregnancy, leading to a decrease in BUN and creatinine.

There is an increase in the renin-angiotensin system, leading to increased aldosterone. But sodium levels remain constant because of the concomitant increase in GFR.

Endocrine

Endocrine changes that occur during pregnancy include increases in:

  • Estrogen

  • Progesterone

  • hCG (human chorionic gonadotropin)

  • hPL (human placental lactogen)

  • Total T4

  • TBG (thyroxine binding globulin)

The maternal adrenal gland produces estrogen precursors, which are converted to estrogen by the placenta.

Levels of estrogen in pregnancy correlate with fetal well-being; low estrogen levels are associated with complications such as fetal death and anencephaly.

Estrogen stimulates the synthesis of thyroid binding globulin, which increases the overall levels of T3 and T4. Free T3 and T4 may increase slightly, but stay within normal ranges.

Human chorionic gonadotropin (hCG) is a marker of pregnancy and follows the following course:

  • Doubles every 48 hours until reaching a peak at around 12 weeks

  • Declines through week 15

  • In a steady state until the end of pregnancy

Metabolic functions of hPL:

  • Decreases maternal insulin sensitivity leading to an increase in maternal blood glucose levels; this is believed to be one of the major causes of Gestational Diabetes.

  • Decrease maternal glucose utilization, which helps ensure adequate fetal nutrition (the mother responds by increasing beta cells). Chronic hypoglycemia leads to a rise in hPL.

  • Increases lipolysis with the release of free fatty acids. With fasting and release of hPL, free fatty acids become available for the maternal organism as fuel, so that relatively more glucose can be utilized by the fetus. Also, ketones formed from free fatty acids can cross the placenta and be used by the fetus.

These functions help support fetal nutrition even in the case of maternal malnutrition.

Hematologic

Hematologic changes that occur during pregnancy include an increase in:

  • Plasma volume

  • RBC volume

  • WBC count

Pregnancy leads to a 50% increase in plasma volume, but only a 30% increase in RBC volume, which results in dilutional anemia.

The normal platelet count is minimally changed during pregnancy and a value below 100 million/mL or a precipitous drop should be worked up. Note: pregnancy is a hypercoagulable state and there is an increase in the incidence of thromboembolic events.

Low risk activities that can continue during pregnancy include:

  • Exercise, which is encouraged to improve well-being, promote healthy blood sugar levels, and reduce symptoms caused by positional changes of the fetus

  • Sexual intercourse, unless the mother is considered high risk for spontaneous abortion, placenta previa, or premature labor

MSK

Musculoskeletal changes include:

  • Increased lumbar lordosis

  • Relaxation of ligaments (in preparation for labor)

  • Stretching and weakening of abdominal musculature

All of these changes can lead to back pain, especially in the lumbar region and sacroiliac joints.

GI

Gastrointestinal changes that occur during pregnancy include:

  • Delayed stomach emptying

  • Decreased lower esophageal sphincter tone

  • Decreased colonic motility

Upper gastrointestinal tract changes (delayed stomach emptying and decreased lower esophageal sphincter tone) result in nausea and vomiting (morning sickness) and reflux. The morning sickness typically resolves around 14-16 weeks' gestation but reflux persists and often worsens throughout the pregnancy.

Hyperemesis gravidarum is a severe form of morning sickness that can lead to significant weight loss and ketosis.

Lower GI tract changes (decreased colonic motility) lead to constipation and hemorrhoids.

Progesterone relaxes smooth muscle, which decreases colonic motility, and therefore increases water absorption and leads to constipation. Straining then leads to hemorrhoids.

The uterus compresses the pelvic veins, which also increases the risk of hemorrhoids. (Think of how hemorrhoids form in patients with portal hypertension.)

Fetal Well Being

FHR

Fetal heart rate monitoring is the most common method by which fetal well-being is assessed. It can be achieved with an external transducer placed on the uterine fundus or with an internal device placed on the fetal scalp.

A reassuring FHR tracing has:

  • A baseline heart rate between 110-160

  • No decelerations

  • Positive accelerations (abrupt increases in heart rate)

  • Moderate variability (6-25 beats per minute)

A nonreassuring FHR tracing has:

  • Unexplained bradycardia or tachycardia

  • No accelerations

  • Repetitive variable decelerations

  • Any late decelerations

  • No variability

Fetal bradycardia is diagnosed when the FHR is <110. Non-hypoxic causes of fetal bradycardia include:

  • Maternal beta blockers

  • Local anesthetics

  • Congenital heart block

Fetal tachycardia is when the FHR is >160. Causes of fetal tachycardia include:

  • Beta agonists

  • Fever

  • Prematurity

  • Fetal movement

Decelerations

There are three types of fetal heart rate decelerations: early, variable, and late.

Early decelerations:

  • Are characterized by a slow decrease in fetal heart rate- the time from onset to nadir is at least 30 seconds

  • Mirror contractions (the nadir of the deceleration occurs at same time as the peak of the contraction)

They are a result of vagal stimulation from fetal head compression with contractions and are not worrisome.

Variable decelerations are sudden drops in FHR - time from onset to nadir is <30 seconds. There is a steep drop and rapid return to baseline. They are a result of umbilical cord compression.

Late decelerations are a gradual decrease in fetal heart rate. Time from onset to nadir is >30 seconds, and the nadir occurs after the peak of the contraction. They occur in response to uteroplacental insufficiency and may indicate fetal acidosis. They are the most worrisome type of deceleration.

Decelerations are characterized as recurrent when they occur with >50% of contractions in a 20-minute period. They are characterized as repetitive when they occur with each contraction of similar magnitude.

A prolonged deceleration lasts from 2-10 minutes.

Management of nonreassuring FHR tracing:

  • Turn off oxytocin (if it is in use)

  • Give normal saline bolus

  • Administer high flow O2

  • Remove the mother from the supine position and place on the left side to minimize IVC compression

  • Rule out prolapsed umbilical cord with vaginal examination

Amnioinfusion (infusion of saline into the uterine cavity following rupture of membranes) may help alleviate variable decelerations due to cord compression.

If the above resuscitation attempts are not successful in normalizing the fetal monitoring strip, and fetal hypoxia is the probable cause, the fetus must be delivered immediately:

  • If the woman is in stage one of labor this must be done via cesarean section

  • If in stage two an operative vaginal delivery or cesarean section should be performed

Nonstress Test

The nonstress test is a simple test that can be performed after 28 weeks’ gestation that places no stress on the fetus. It is used often both during prenatal assessment and into labor. During the nonstress test, effects of fetal movement on heart rate are noted.

The mother reclines in left lateral supine position and the fetal heart rate is monitored with external fetal heart rate and uterine monitors. A normal or "reactive" test is defined as a 20-minute fetal heart rate tracing that contains:

  • 110-160 beats per minute baseline heart rate

  • Moderate variability (6-25 bpm)

  • Two or more 15 bpm accelerations of fetal heart rate lasting at least 15 seconds each

  • No late, variable, or spontaneous decelerations

For example, if the baseline is 145bpm, the heart rate must rise to at least 160bpm for at least 15 seconds to count as an acceleration, and this must occur twice during the 20-minute test. (In patients less than 32 weeks' gestation, 10 bpm x 10 seconds is adequate.)

An external sound device (vibroacoustic stimulator) can be attached to the patient’s abdomen in order to encourage fetal activity and reduce the time of the test.

An abnormal (nonreactive) test warrants the performance of a biophysical profile. If a prompt induction of labor or vaginal delivery is under consideration (such as when an NST is performed on admission to the labor and delivery unit), then a contraction stress test may be indicated to determine whether the fetus will tolerate labor.

Biophysical Profile

The biophysical profile is a combination of a nonstress test and an ultrasound evaluation, typically performed in the third trimester. It is performed as a follow-up to a nonreactive nonstress test.

Ultrasound is used to measure the amniotic fluid index (discussed in Polyhydramnios), fetal breathing rate, fetal movement, and fetal tone.

The scoring system used in the biophysical profile assigns a value of 2 to satisfactory results and a 0 if criteria is not met (there is no 1 point score).

Criteria that are considered in the biophysical profile include:

  • Reactive nonstress test

  • Amniotic fluid: at least one 2x2cm pocket

  • One or more episode of rhythmic breathing lasting at least 20 seconds within a 30 minute period

  • Two or more episodes of discrete fetal movement within a 30-minute period

  • One or more episodes of spine and limb extension with return to flexion

Score interpretation is complex, and management depends on the clinical situation, gestational age at testing, etc.

In general,

  • a score of 8-10/10 is reassuring

  • a score of 6 is equivocal

  • a score of 4 or less is abnormal

  • a score of 0-2 mandates delivery

Contraction Stress Test

A contraction stress test is performed to assess utero-placental function and determine whether the fetus will tolerate labor.

If the test is positive, cesarean section should be strongly considered.

In a contraction stress test, IV oxytocin (pitocin) is administered and titrated until the patient is having 3-5 contractions in a 10-minute interval.

The contraction stress test is considered positive if there are late decelerations with at least 50% of contractions.

Reassuring signs associated with the contraction stress test include:

  • Moderate variability

  • Occasional heart rate accelerations (two or more of 15 bpm lasting at least 15 seconds within a 20 minute period)

Note: Early decelerations may be seen, and are not concerning.

Fetal Scalp Monitoring

Fetal scalp monitoring tracks:

  • Pulse oximetry

  • Continuous fetal heart rate monitoring

  • Electrocardiogram via a monitor attached to the fetal scalp

Fetal scalp monitoring should only be used in pregnancies >36 weeks’ gestation with the fetus in vertex position and ruptured membranes.

Fetal scalp blood sampling is performed when a fetal heart rate tracing is consistently abnormal and other lower risk modalities (e.g., amniocentesis, chorionic villous sampling) are not warranted due to lack of information or timeliness.

Normal fetal blood pH is reassuring, but decreased pH, hypoxemia, and increased lactate indicate fetal distress.

Diagnosis, Dating, Terminology

Pregnancy is first suspected when a sexually active woman with normal menstrual cycles misses her period by a few days to a week.

Symptoms that are also suggestive of pregnancy are:

  • Amenorrhea

  • Nausea and vomiting

  • Breast pain

  • Quickening (first fetal movements felt by the mother)

Over the counter and hospital laboratory urine pregnancy tests detect β-hCG in the urine.

The definitive test for diagnosing pregnancy is ultrasound revealing a gestational sac.

Evaluating and treating a pregnant woman requires an understanding of her obstetrical history.

  • Gravidity is the number of times a woman has been pregnant.

  • Parity is the number of pregnancies that resulted in delivery at 20 weeks gestational age or more not the number of children that resulted.

  • Parity is sometimes expanded to GTPAL, for Gravida (number of pregnancies), number of pregnancies leading to Term births (37+ weeks), number of pregnancies leading to Preterm births (20-36 weeks), Abortions (spontaneous <20 weeks or elective), and Living children.

For example:

  • A woman with two pregnancies and 2 term births would be G2P2, or G2P2002.

  • A woman currently pregnant with her second after one preterm birth would be G2P1 (or G2P0101) since the second has not yet been born.

  • A woman with a single pregnancy that delivered twins at 36 weeks would be G1P0102 (one pregnancy, one pregnancy that led to delivery at <37 weeks' gestation, two living children).

There are a number of methods available to estimate gestational age and due date. The most accurate of these methods is measurement of crown-rump-length (CRL) by ultrasound, performed between 7 and 14 weeks of gestation. It is most accurate between 7 and 10 weeks (± 3 days).

For patients who are pregnant following use of assisted reproductive technology (ART: IVF or IUI), the ART-derived due date should be used.

The gestational age (GA) of a fetus is measured from the last menstrual period (LMP).

The Nagele rule is used to estimate the date of delivery using the last menstrual period (LMP). To estimate, you:

  • Subtract 3 months from the LMP

  • Add 1 year

  • Add 7 days

Gestational age can also be determined by ultrasound. However, ultrasound dating becomes more uncertain as the pregnancy progresses.

Prenatal Diagnosis of Anomalies

Specialized tests are indicated in women who have an increased risk for giving birth to children with congenital abnormalities. Risk factors include:

  • Advanced maternal age (>35 years)

  • History of spontaneous abortion

  • Teratogen exposure

  • Diabetes mellitus

  • History of fetal demise

Fetal Cell Free DNA

Fetal cell-free DNA (aka NIPT) is the latest test on the market. It detects fetal DNA in maternal blood and is used to test for trisomies in singleton pregnancies age 7 weeks' gestational age or greater. It is currently indicated in mothers with a high risk of genetic abnormalities (advanced maternal age, history of trisomy in a prior pregnancy, etc).

Of note, while it is extremely accurate, this test is still considered a screening test and abnormal results should be followed up with a definitive diagnostic test such as amniocentesis.

Chorionic Villi Sampling

Chorionic villi sampling involves transabdominal or transcervical aspiration of chorionic villus tissue at 9-12 weeks in order to detect genetic abnormalities.

It provides for earlier detection of genetic abnormalities in women who are consider higher risk patients, such as:

  • Advanced maternal age (>35 years)

  • History of children with genetic defects

Umbilical Cord Sampling

Percutaneous umbilical cord sampling is a procedure where blood is collected from the umbilical vein after 18 weeks’ gestation to identify chromosomal defects, fetal infection, or Rh sensitization.

This procedure is indicated for late detection of genetic disorders or pregnancies with a high risk of Rh sensitization.

Amniocentesis

Amniocentesis involves transabdominal needle aspiration of amniotic fluid from the amniotic sac after 16 weeks’ gestation in order to measure amniotic alpha-fetoprotein and to determine the fetal karyotype.

This test detects neural tube defects and chromosome disorders with greater sensitivity than triple screen alone.

Amniocentesis is indicated in women who:

  • Had an abnormal quadruple screen

  • Women >35 years of age

  • Have a risk of Rh sensitization

This procedure carries an additional 1% risk of spontaneous abortion over normal risks for abortion. Other risks include:

  • Rupture of membranes

  • Chorioamnionitis

  • Injury to fetal structures

  • Maternal alloimmunization

Quadruple Screen

At around 16-20 weeks’ gestation a quadruple screen should be performed to look for trisomies 18 and 21. It is only valid during this time frame. The quadruple screen consists of:

  • Maternal serum alpha-fetoprotein

  • hCG level

  • Unconjugated estriol

  • Maternal serum inhibin A

Remember that high levels of maternal serum alpha-fetoprotein are associated with increased risk of neural tube defects.

Results associated with trisomy 21 include:

  • Decreased alpha-fetoprotein

  • Decreased unconjugated estriol

  • Increased hCG

  • Increased inhibin A

Results associated with trisomy 18 include:

  • Decreased alpha-fetoprotein

  • Very decreased unconjugated estriol

  • Very decreased hCG

  • Normal inhibin A

An abnormal quadruple screen should be followed up with an ultrasound and a definitive genetic test such as amniocentesis.

Full Integrated Test

Full integrated test is an ultrasound measurement of nuchal translucency (NT) and measurement of maternal serum pregnancy-associated plasma protein A (PAPP-A) in the first trimester with follow-up quadruple screening (covered below) in the 2nd trimester.

The full integrated test is indicated in women who desire noninvasive testing during the first trimester with the lowest false positive rate.

Results associated with trisomy 21 include:

  • Decreased PAPP-A

  • Increased hCG

  • Increased NT

Results associated with trisomy 18 include:

  • Very decreased PAPP-A

  • Very decreased hCG

  • Increased NT

Increased NT is seen in trisomy 13, as with the other trisomies. Other findings are variable and may often be normal.

An abnormal integrated test should be followed up with an ultrasound and a definitive genetic test such as an amniocentesis.

Sequential Screen

The sequential screen consists of several components: first-trimester maternal serum testing for hCG and PAPP-A, nuchal translucency measurement by ultrasound, and second-trimester maternal serum testing. This is more accurate than the quad screen alone, but is still less accurate than chorionic villus sampling.

Prenatal Nutrition

Foods that should be avoided in pregnancy include:

  • High mercury content seafood

  • Unpasteurized foods, including soft cheeses made from unpasteurized milk

  • Caffeine intake higher than 200mg/day (there is minimal evidence of increased miscarriage risk due to high caffeine intake, but many providers still recommend limiting caffeine intake)

  • Deli meats and hot dogs (unless re-heated to steaming hot)

  • Uncooked, refrigerated, smoked seafood (i.e. lox, kippers)

The average woman needs an additional 300 kcal/day when pregnant and 500 kcal/day when breastfeeding. The daily caloric intake during pregnancy should be approximately 2,500 kcal/day.

Weight

Appropriate weight gain is based on pre-pregnancy BMI.

  • 28-40 lb for patients with a BMI < 18.5

  • 25-35 lb for patients with a BMI between 18.5 and 24.9

  • 15-25 lb for patients with a BMI between 25 and 29.9

  • 11-20 lb for patients with a BMI > 30

Excessive weight gain during pregnancy can lead to:

  • Complications of pregnancy (such as fetal macrosomia, gestational diabetes, etc)

  • Postpartum water retention

  • Long-term obesity

Vitamins

Vitamin and mineral levels become increasingly important for an expecting mother due to the adverse effects of nutritional deficiencies on the fetus. It is extremely important to advise all pregnant women as well as those who might become pregnant to take a daily prenatal vitamin containing at least 400mcg (0.4mg) of folate.

Calcium (1-1.3 g/day, which is a 50% increase) for lactation reserves and increased utilization by the fetus. Insufficient calcium intake is linked to:

  • Impaired maternal bone mineralization (osteopenia and osteoporosis)

  • Hypertensive disorders of pregnancy including pre-eclampsia and eclampsia

  • Premature birth

  • Low birth weight

Folate (0.4-0.8 mg/day, which should begin 4 weeks before attempting conception) to support normal fetal neural tube development. Insufficient folate intake is linked to neural tube defects.

Additional fluid intake is necessary to support the increased total maternal-fetal fluid volume.

Protein (60 g/day, which is a 30% increase) to support the additional needs of maternal, fetal, and placental tissue. Insufficient protein intake is linked to impaired fetal and placental growth.

Iron (30 mg/day, which is a 100% increase) for RBC production. Insufficient iron intake is linked to:

  • Maternal anemia

  • Premature birth

  • Low birth weight

  • Maternal cardiac complications

Women at risk for poor nutrition during pregnancy include:

  • Teenagers

  • Lower socioeconomic status

  • Adherence to diets with certain food restrictions

  • Underweight

  • Smokers, alcoholics, or drug abusers

Routine Prenatal Care

Prenatal visits are an important part of pregnancy, not only to screen for maternal and fetal complications, but to educate the expecting mother. At each visit the woman should be asked the A, B, C, D, E, F questions to rule out complications:

  • Amniotic fluid leaking?

  • Vaginal Bleeding?

  • Contractions?

  • Dysuria?

  • Eclampsia symptoms – headache, vision changes, swelling?

  • Fetal movements?

These questions make up the obstetric portion of the review of systems (just like you ask every patient about fevers, chills, chest pain, etc).

During every visit, the following labs/measurements should be taken:

  • Maternal weight gain

  • Urinalysis (usually a urine dipstick) looking for: UTIs, proteinuria, or glucosuria

  • Blood pressure

  • Fundal height to estimate fetal growth

  • Fetal heart sounds to reassure viability

If only a single screening ultrasound examination is performed, the optimal timing is at 18 to 22 weeks of gestation. This is used to assess for gross fetal abnormalities and to determine the position of the placenta (keeping in mind that the vast majority of patients with placenta previa on second trimester ultrasound will have normal placental location at term).

The first dose of Rho(D) immune globulin (RhoGAM) should be administered at 28wga to Rh negative mothers to prevent formation of anti-Rh antibodies in the mother following mixing of Rh-negative maternal blood and Rh-positive fetal blood during delivery. Formation of these antibodies, known as sensitization, can lead to hemolytic disease of the newborn in subsequent pregnancies.

Note: After delivery, the newborn's blood type should be determined and, if Rh-positive, the mother should receive a second dose of RhoGAM in the immediate postpartum period.

All pregnant women should be screened for asymptomatic bacteriuria between 11 and 16 weeks gestation and should be appropriately treated if the urine culture is positive.

All patients should receive a Tdap vaccine at 27-36 weeks' gestational age, to provide additional pertussis protection to the neonate following delivery via transplacental transfer of maternal anti-pertussis IgG.

At 35-37 weeks’ gestation, all patients should be screened for anogenital group B streptococcus colonization. Repeat screening for chlamydia and gonorrhea is indicated only in high-risk patients.

At 24-28 weeks’ gestation, a 1 hour glucose challenge should be administered to screen for gestational diabetes mellitus.

Labs indicated in high risk patients include screening for:

  • Tuberculosis with purified protein derivative

  • Anemias using red blood cell indices and hemoglobin electrophoresis

  • Metabolic diseases(hexosaminidase A for Tay-Sachs, phenylalanine for phenylketonuria)

  • Hepatitis C serology

  • Toxoplasmosis

  • Cystic fibrosis

Fetal Development

Gestational age can be calculated with Naegle’s rule, which is covered in the topic Diagnosis, Dating, and Terminology of Pregnancy.

Embryonic and fetal development begins with fertilization. Fetal maturity takes place in approximately 38 weeks. All ages are given as gestational age (ovulation age + 2 weeks).

Fertilization occurs on approximately cycle day 14 (gestational age 2 weeks + 0 days), and the blastocyst enters the uterine cavity 3 days later (2 weeks + 3 days).

Day 6 after fertilization (gestational age 2 weeks + 6 days) is marked by implantation of the embryo and the formation of the early placenta from trophoblastic cells, which produce b-hCG.

In gestational week 3:

  • Early lacunae of the placenta form

  • The neural tube develops

  • The primitive tubular heart develops

In gestational week 4:

  • The diaphragm forms

  • The lungs begin to develop

  • The GI tract begins to develop

  • The urinary tract begins to develop

  • The genitals begin to develop but are not yet visible on ultrasound

  • The eyes begin to develop

  • Limb buds appear

During week 5:

  • The face starts to develop

  • The vertebrae of the spine develop

During week 7, the inner ear develops.

The fetal kidneys begin to function during week 9.

At week 12 the fetal sex is easy to distinguish and the biliary system begins to form.

At week 17 there is early detectable fetal movement.

At week 20 the fetal pancreas begins to function.

At week 24, surfactant production begins and fingernails present. This is the earliest chance of survival with premature birth.

At week 28, eyes open and hair develops.

At week 30, the fetus takes on a chubby body appearance, resembling the mature fetal form.

At week 32, the fetus usually survives if it is born prematurely.

A firm grasp develops at week 35.

At 37 weeks the fetus is considered "early term." At 39 weeks, the fetus reaches "full term." 41 weeks to 41 weeks and 6 days is "late term." After 42 weeks is "post term."

Normal Postpartum

Following delivery, the uterus will decrease in size and the cervix will become firm over the next three weeks. The vaginal wall will gradually become firmer.

Postpartum maternal changes involve anatomical, physiological, and psychological changes, which ultimately resolve to a pre-pregnancy state within 6 weeks of delivery.

Lochia (uterine discharge following delivery) is red initially, but becomes paler and white by the 10th day following delivery.

Total peripheral resistance increases as uteroplacental circulation is no longer present, diuresis causes significant weight loss in the first week following delivery, and cardiac output gradually returns to normal.

Mild depression, called “postpartum blues” or “baby blues” may affect the mother for up to two weeks following delivery. Postpartum blues does not affect the mother’s ability to care for herself or the newborn and it does not include psychosis, unlike postpartum depression. It generally resolves without complications.

In non-nursing mothers menstruation should return about 6-8 weeks following delivery.

If nursing, ovulation and menstruation may not occur for months. If nursing is performed regularly, this method of contraception should still be paired with another method of contraception as return of menstruation can be unpredictable.

Immediate postpartum care of the newborn in the delivery room is often performed by the delivering provider and includes both routine management and assessment of the newborn.

Suctioning of the mouth and nares with either a bulb syringe or a suction catheter immediately following birth should be performed in newborns with obvious obstruction due to secretions or those that require positive pressure ventilation.

To prevent heat loss, the newborn should be dried and wrapped in clothes.

The umbilical cord should be clamped and cut and a blood sample should be taken from the cord in order to measure blood gases and blood type.

Respiration should begin within 30 seconds of delivery. If not, resuscitation must be initiated.

If the lungs are immature, tracheal injection of synthetic or exogenous surfactant may be given.

An Apgar score is performed both 1 and 5 minutes after birth. A score of 7+ at 1 minute and 9+ at 5 minutesare reassuring scores. About 90% of infants have an apgar score within this range.

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