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Am Fam Physician. 2023;108(2):139-150

Related editorial: Perinatal Care of Transgender Patients, Adolescent Patients, and Patients With Opioid Use Disorder

This clinical content conforms to AAFP criteria for CME.

Author disclosure: No relevant financial relationships.

Well-coordinated prenatal care that follows an evidence-based, informed process results in fewer hospital admissions, improved education, greater satisfaction, and lower pregnancy-associated morbidity and mortality. Care initiated at 10 weeks or earlier improves outcomes. Identification and treatment of periodontal disease decreases preterm delivery risk. A prepregnancy body mass index greater than 25 kg per m2 is associated with gestational diabetes mellitus, hypertension, miscarriage, and stillbirth. Advanced maternal and paternal age (35 years or older) is associated with gestational diabetes, hypertension, miscarriage, intrauterine growth restriction, aneuploidy, birth defects, and stillbirth. Rho(D) immune globulin decreases alloimmunization risk in a patient who is RhD-negative carrying a fetus who is RhD-positive. Treatment of iron deficiency anemia decreases the risk of preterm delivery, intrauterine growth restriction, and perinatal depression. Ancestry-based genetic risk stratification using family history can inform genetic screening. Folic acid supplementation (400 to 800 mcg daily) decreases the risk of neural tube defects. All pregnant patients should be screened for asymptomatic bacteriuria, sexually transmitted infections, and immunity against rubella and varicella and should receive tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap), influenza, and COVID-19 vaccines. Testing for group B Streptococcus should be performed between 36 and 37 weeks, and intrapartum antibiotic prophylaxis should be initiated to decrease the risk of neonatal infection. Because of the impact of social determinants of health on outcomes, universal screening for depression, anxiety, intimate partner violence, substance use, and food insecurity is recommended early in pregnancy. Screening for gestational diabetes between 24 and 28 weeks is recommended for all patients. People at risk of preeclampsia, including those diagnosed with COVID-19 in pregnancy, should be offered 81 mg of aspirin daily starting at 12 weeks. Chronic hypertension should be treated to a blood pressure of less than 140/90 mm Hg.

Family physicians provide family-centered care for individuals and families before, during, and after the birth of a child. Well-coordinated prenatal care that follows an evidence-based, informed process results in fewer hospital admissions, improved education, greater care satisfaction, improved perinatal outcomes, and mitigates pregnancy-associated morbidity and mortality.1 Family physicians are uniquely positioned to address social determinants of health while ensuring quality of care.

Clinical recommendation Evidence rating Comments
In patients who are RhD-negative carrying a fetus who is RhD-positive, administer Rho (D) immune globulin to decrease the risk of alloimmunization.41 A Evidence demonstrating reduced Rh alloimmunization after exposure to Rh-positive fetal blood
Consider intravenous iron for patients who cannot tolerate oral iron or in whom oral iron has been ineffective at correcting the deficiency.43 C Cohort studies demonstrating higher maternal hemoglobin at delivery and six weeks postpartum
Recommend 400 to 800 mcg of folic acid daily for patients of reproductive age who may become pregnant.35 A Cohort studies and randomized trials demonstrating protection against neural tube defects in people taking folic acid
Prescribe daily aspirin (81 mg) for the prevention of preeclampsia starting at 12 weeks in patients at high risk of developing preeclampsia.5 B Cohort studies demonstrating statistically significant reduction in preeclampsia risk among those taking low-dose aspirin
Assess cervical length from 16 through 24 weeks in patients with a previous preterm delivery and treat with progesterone supplementation.82 B Cohort studies and randomized controlled clinical trials demonstrating delayed labor onset
Recommend breastfeeding as the best feeding method for most infants.23 A Cohort studies and clinical trials demonstrating improved outcomes for breastfeeding infants
Screen all pregnant patients for hepatitis C, regardless of risk.55 C Expert opinion in the absence of clinical trials
RecommendationSponsoring organization
Do not perform maternal serologic studies for cytomegalovirus and toxoplasmosis as part of routine prenatal laboratory studies.Society for Maternal-Fetal Medicine
Do not perform prenatal ultrasonography for nonmedical purposes (e.g., solely to create keepsake videos or photographs).American College of Obstetricians and Gynecologists
Do not perform third trimester group B Streptococcus culture in patients with group B Streptococcus bacteriuria during current pregnancy.Society for Maternal-Fetal Medicine

Prenatal Care Visits

Initiation of care between six and 10 weeks allows for identification of preexisting conditions that negatively affect maternal-fetal outcomes (e.g., diabetes mellitus, hypertension, obesity)2; however, 22% of pregnant patients do not receive care during this time.2 The COVID-19 pandemic resulted in a reevaluation of the number of physician visits needed, with an emphasis on increased flexibility, allowing for a combination of virtual and in-person visits depending on risk.3 Table 1 outlines the components of prenatal care.1,422 Table 2 provides opportunities for educating pregnant patients during prenatal care visits.6,8,1419,2329

Physical examination
Abdominal palpation1,4 Leopold maneuvers can be used to assess fetal presentation beginning at 36 weeks
Blood pressure measurement5 Should be assessed at each prenatal visit
Body mass index6 Should be determined at first prenatal visit; weight should be measured at all subsequent visits
Dental health7 Should be assessed at initial prenatal visit; treatment of periodontal disease can decrease risk of preterm delivery
Fetal heart rate1,8 Auscultation should be performed at each prenatal visit to confirm a viable fetus, although there is no evidence of other clinical or predictive value
Fundal height measurement1,8 Recommended at each prenatal visit beginning at 20 weeks; should be plotted for monitoring purposes
Prenatal ultrasonography
Fetal anatomy screening9 Should be evaluated with ultrasonography between 18 and 22 weeks
Dating9,10 Ultrasonography dating is considered accurate to within:
 5 days if less than 8 6/7 weeks
 7 days between 9 0/7 and 15 6/7 weeks
 10 days between 16 0/7 and 21 6/7 weeks
 14 days between 22 0/7 and 27 6/7 weeks
 21 days if more than 28 0/7 weeks
Screening for psychosocial factors
Depression and anxiety-related disorders11 Screening is recommended in first and third trimesters using validated tools
Anxiety: Generalized Anxiety Scale-7 (sensitivity 73%, specificity 67%) or State-Trait Anxiety Inventory (sensitivity 81%, specificity 78%)
Bipolar disorder: screening should occur before initiating treatment for anxiety or depression; Composite International Diagnostic Interview (sensitivity 69% to 100%, specificity 98% to 99%) or Mood Disorder Questionnaire (sensitivity 44% to 90%, specificity 61% to 92%)
Depression: Edinburgh Postnatal Depression Scale (sensitivity 81%, specificity 88%) or Patient Health Questionnaire-9 (sensitivity and specificity 88%), which contains questions about anxiety
Food insecurity12 Patients should be screened at least once during pregnancy and in the postpartum period; two-item validated Hunger Vital Sign screening tool (sensitivity 97%)
Intimate partner violence13 Patients who may become pregnant should be screened and provided with intervention services for positive results
Substance use1419 Pregnant patients should be asked about alcohol consumption, tobacco use, and illicit drug use during the first prenatal visit
Use of validated tools to screen for opioid use is encouraged (e.g., 4Ps [parents, partners, past, and pregnancy], NIDA Quick Screen, CRAFFT [car, relax, alone, forget, friends, trouble])
Counseling is effective in decreasing substance use in pregnancy and associated infant morbidity (e.g., intrauterine growth restriction); therefore, individualized, pregnancy-tailored counseling and treatment should be offered
Antenatal fetal surveillance and delivery timing
Antenatal fetal surveillance (e.g., non-stress testing, biophysical profile)20 Recommended in pregnancies complicated by conditions that increase the risk of stillbirth, including: intrauterine growth restriction, hypertension, diabetes mellitus, prepregnancy body mass index greater than 35 kg per m2, five or more alcoholic drinks per week, substance use, gestational age 41 0/7 weeks and greater
Timing and frequency of testing should be determined in consultation with perinatology
Delivery timing21,22 Can offer elective induction of labor at 39 weeks for low-risk, singleton pregnancies
Determination of optimal timing for delivery of pregnancies complicated by high-risk fetal, placental, and maternal conditions should be done in consultation with perinatology
Air travel17 Generally safe in pregnancy up to 36 weeks; long flights are associated with an increased risk of venous thrombosis
Availability of medical resources at the destination should be considered; the Centers for Disease Control and Prevention provides information for pregnant travelers (
Breastfeeding23 Recommended as the best feeding method for most infants
Contraindications include: maternal HIV, untreated brucellosis, active herpetic lesions on the breast, cracked nipples with hepatitis C infection, use of illicit substances (e.g., nonparenteral opioids, cocaine, phencyclidine), and use of certain medications
Structured behavior counseling, one-on-one needs-based counseling, and education programs increase breastfeeding success
Childbirth education8 Common part of prenatal care in the United States; although it may increase confidence, it does not change the experience of labor or birth outcomes
Exercise17 At least 30 minutes of moderate exercise five days per week is a reasonable goal for most pregnant or postpartum patients
Pregnant patients should avoid activities that put them at risk of falls or abdominal injuries
Fetal movement counts24 Routine counting increases patient anxiety and triage evaluations, prenatal testing, and interventions without improving outcomes
Gestational weight gain6 Prepregnancy body mass index (kg per m2):
 < 18.5
 18.6 to 24.9
 25 to 29.9
 ≥ 30
Recommended weight gain:
 28 to 40 lb (13 to 18 kg)
 25 to 35 lb (11 to 16 kg)
 15 to 25 lb (7 to 11 kg)
 11 to 20 lb (5 to 9 kg)
Herbal therapies8,17 Pregnant patients should avoid anything with known harmful effects to the fetus, such as ginkgo, ephedra, and ginseng, and should be cautious of substances with unknown effects
Labor and delivery17 Pregnant patients should be counseled about what to do when their membranes rupture, what to expect when labor begins, strategies to manage pain, and the value of having support during labor
Medications (prescription and over-the-counter)17 Risks and benefits of individual medications should be reviewed because few medications have been proven safe for use during pregnancy, particularly during the first trimester
Seat belt use17 Pregnant patients should use a three-point seat belt
Sex8,17 Most pregnant people may continue to have sex throughout pregnancy; however, in certain situations (e.g., placenta previa), abstaining from sex is recommended
Environmental and occupational exposures
Cat litter17 Avoid contact to reduce the risk of toxoplasmosis
Excretion of Toxoplasma gondii oocytes by cats poses risk of transmission to humans who have contact with contaminated litter; hand hygiene is recommended
Hair treatments17 Although hair dyes and treatments have not been explicitly linked to fetal malformation, they should be avoided during early pregnancy
Heat exposure17,25 Extreme heat, including hot tubs and saunas, should be avoided during the first trimester because it has been associated with congenital anomalies (i.e., neural tube defects, certain cardiac defects, and miscarriage)
Heavy metals26 Exposure should be avoided during early pregnancy because of the potential for delayed fetal neurologic development
Radiation27 Pregnant people should avoid ionizing radiation because it may affect fetal thyroid development
Adverse fetal effects are not associated with radiography that is in a normal diagnostic range (less than 50 mGy) and that avoids direct abdominal views; ultrasonography; or use of microwaves, computers, or cell phones
Solvents28 Pregnant people should avoid exposure to solvents (e.g., toluene, benzene), particularly in areas without adequate ventilation
Exposure has been associated with an increase in miscarriage, stillbirth, preterm birth, and intrauterine growth restriction
Workplace accommodations29 Working, in general, is safe during pregnancy; however, some conditions, such as prolonged standing and exposure to certain chemicals, are associated with pregnancy complications
Physician-ordered accommodations for pregnant people can ensure safe working conditions
Substance use
Substance use1419 No amount of alcohol, tobacco, or illicit drug use has been proven to be safe during pregnancy


Weight, height, and blood pressure should be measured at the first prenatal visit. Early identification of periodontal disease and treatment decreases adverse pregnancy outcomes.7 Treatment may be performed in the second trimester, and emergent treatment may be completed at any time during pregnancy.7 A bimanual pelvic examination has poor predictive value for clinical pelvimetry and screening for disease (i.e., sexually transmitted infections and cancer) but may be used as a diagnostic aid in patients with a discrepancy between uterine size and gestational age, which warrants ultrasonography assessment.30 A pelvic examination is also useful in a symptomatic patient for evaluating spontaneous labor (e.g., cervical dilation, rupture of amniotic membranes). The clinical breast examination is a diagnostic aid in the symptomatic patient and addresses breastfeeding concerns or barriers but does not demonstrate benefit in patients already receiving screening mammograms and does not decrease mortality.3133


A prepregnancy body mass index (BMI) greater than 25 kg per m2 is associated with preterm delivery, gestational diabetes, gestational hypertension, and preeclampsia. A BMI greater than 30 kg per m2 is also associated with an increased risk of miscarriage, stillbirth, and obstructive sleep apnea.6 Prepregnancy BMI informs the timing of fetal surveillance, nutritional counseling, and goals for gestational weight gain. Table 3 lists general dietary guidelines for pregnant people.8,17,34,35 For Black and Hispanic people, a prepregnancy BMI greater than 25 kg per m2 and the associated poor outcomes are worse compared with non-Hispanic White people.36

Artificial sweeteners17 Minimize intake of food and drinks containing saccharinSaccharin is known to cross the placenta and may remain in fetal tissue
Aspartame, sucralose, and acesulfame-K are probably safe
Caffeine8,17 Limit consumption to no more than 300 mg per day; moderate amounts are probably safeObservational studies show an association between high caffeine consumption and spontaneous abortion and low birth weight
Calorie intake34 Most pregnant people require an additional 300 to 400 calories per dayWeight gain guidelines have varied and are based on limited data
Dairy8,17 Avoid unpasteurized dairy products and soft cheeses (e.g., feta, Brie, Camembert, blue-veined cheeses, Mexican queso fresco)Risk of Toxoplasma and Listeria contamination, based on case reports
Delicatessen foods8,17 Avoid delicatessen foods, pâté, and meat spreadsRisk of Listeria contamination, based on case reports
Eggs17 Avoid raw eggs (e.g., Caesar salad, eggnog, raw cookie dough)Risk of salmonella contamination, based on case reports
Folic acid35 Initiate 400 mcg daily of folic acid as early as four weeks before conception
Initiate 4 mg daily of folic acid as early as three months before conception for patients taking folate antagonists
Decreases the risk of neural tube defects
Fruits and vegetables17 Wash fruits and vegetables before eating
Wash cutting boards, dishes, utensils, and hands with hot, soapy water after contact
Risk of Toxoplasma and Listeria contamination, based on case reports
Herbal teas17 Avoid teas containing chamomile, licorice, peppermint, or raspberry leafSome herbal teas have been associated with adverse outcomes, such as uterine contraction, increased uterine blood flow, and spontaneous abortion, in low-quality studies
Teas containing ginger, citrus peel, lemon balm, and rose hips are probably safe in moderation
Leftover foods17 Thoroughly reheat before eatingRisk of Listeria contamination, based on case reports
Meat8,17 Avoid undercooked meat; hot dogs and cold cuts should be heated until steaming hot
Wash cutting boards, dishes, utensils, and hands with hot, soapy water after contact with uncooked meat
Eat liver and liver products in moderation
Risk of Toxoplasma and Listeria contamination with undercooked meats, based on case reports
Excessive consumption of liver products could cause vitamin A toxicity
Seafood8,17 Avoid shark, swordfish, mackerel, tilefish, and tuna steaks; limit intake of other fish (including canned tuna) to 12 oz per weekExposure to high levels of mercury in certain fish can lead to neurologic abnormalities in pregnant patients and infants
Avoid refrigerated smoked seafoodRisk of Listeria contamination with refrigerated smoked seafood, based on case reports
Avoid raw fish and shellfishRisk of exposure to parasites and Norovirus with raw fish and shellfish, based on case reports
Eat farmed salmon in moderationIncreased levels of organic pollutants, including polychlorinated biphenyls and dioxins, have been found in farmed salmon


Advanced maternal and paternal age (35 years and older) is associated with poor outcomes (i.e., aneuploidy, birth defects, gestational diabetes, hypertension, intrauterine growth restriction [IUGR], miscarriage, and stillbirth). Activities focused on improving perinatal outcomes for this group, such as a detailed fetal anatomic screening on ultrasonography, may decrease morbidity and mortality.37

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