Comprehensive Antenatal Care: A Clinicosocial Framework
Antenatal care should consist of a minimum of 8 contacts throughout pregnancy with structured screening, interventions, and psychosocial support distributed across trimesters to optimize maternal and neonatal outcomes. 1
Preconception and First Trimester (Before 16 weeks)
Initial Assessment and Risk Stratification
Laboratory screening should include complete blood count, urinalysis, blood type and screen, rubella serology, syphilis screening, hepatitis B surface antigen, HIV testing, gonorrhea and chlamydia screening, diabetes screening, and cervical cytology as indicated. 2 Consider thyroid-stimulating hormone measurement, particularly in women with risk factors. 2
Genetic and family history assessment must evaluate risk of chromosomal or genetic disorders based on family history, ethnic background, and maternal age, with cystic fibrosis and other carrier screening offered as indicated. 2
Physical examination should focus specifically on periodontal, thyroid, heart, breast, and pelvic examinations—not just a general assessment. 2
Critical Early Interventions
Folic acid supplementation (400-800 mcg daily) must be initiated before conception or immediately upon pregnancy recognition, as neural tube closure occurs at 6 weeks gestation (28 days post-conception), making later supplementation ineffective for neural tube defect prevention. 2, 1
Low-dose aspirin (81-150 mg daily) should be started before 16 weeks of gestation for women with preeclampsia risk factors including: chronic hypertension, pregestational diabetes, BMI >30, chronic kidney disease, antiphospholipid syndrome, prior preeclampsia, or ≥2 minor risk factors (advanced maternal age, family history of preeclampsia, primiparity, connective tissue disorders). 1 This represents a critical window—starting aspirin after 16 weeks significantly reduces efficacy. 1
Calcium supplementation (1200 mg daily) should be provided if dietary calcium intake is low. 1
Medication and Teratogen Review
All current medications must be reviewed to avoid FDA pregnancy category X medications and most category D medications unless maternal benefits clearly outweigh fetal risks. 2 Specifically discontinue ACE inhibitors, ARBs, statins, isotretinoin, warfarin, and review antiseizure medications. 2, 1 Include assessment of over-the-counter medications, herbs, and supplements. 2
Infection Screening and Immunization
Screen for periodontal, urogenital, and sexually transmitted infections as indicated by risk factors. 2 Update immunizations with hepatitis B, rubella, varicella, Tdap, human papillomavirus, and influenza vaccines as needed, counseling about preventing TORCH infections (Toxoplasmosis, Other viruses, Rubella, Cytomegalovirus, Herpes simplex). 2
Nutritional Assessment
Assess the "ABCDs" of nutrition: anthropometric factors (BMI), biochemical factors (anemia), clinical factors, and dietary risks. 2 Potassium iodide supplementation (150 mcg daily) should be provided. 1
Psychosocial Screening
Screen for depression, anxiety, domestic violence, and major psychosocial stressors using validated tools. 2 Assess substance use including tobacco, alcohol, and drugs using CAGE or T-ACE questionnaires. 2 For tobacco users, implement the five A's approach: Ask, Advise, Assess, Assess, Arrange for smoking cessation. 2
Counsel about environmental and occupational exposures to heavy metals, solvents, pesticides, endocrine disruptors, and allergens at home, neighborhood, and workplace, reviewing Material Safety Data Sheets and consulting teratology information specialists as needed. 2
Special Considerations for Pregestational Diabetes
Women with type 1 or type 2 diabetes require intensive preconception optimization with target HbA1c <6.5% before conception to reduce risk of congenital anomalies. 1 Multidisciplinary care should include endocrinologist, maternal-fetal medicine specialist, registered dietitian, and diabetes educator. 1
Comorbidity screening must include foot examination, dilated eye examination, thyroid function testing, urinary protein evaluation, and electrocardiogram. 2, 1
Second Trimester (14-28 weeks)
Structural Assessment
Detailed fetal anatomy ultrasound should be performed at the standard 18-22 week timeframe. 2, 1
Fetal echocardiogram is indicated for women with pregestational diabetes due to increased risk of fetal hypertrophic cardiomyopathy. 2, 1
Ongoing Interventions
Continue low-dose aspirin for preeclampsia prevention in at-risk women. 2, 1
Dilated eye examination should be performed for women with preexisting diabetes to monitor for development or progression of diabetic retinopathy. 1
Hemoglobin Assessment
Hemoglobin determination is more critical around week 30 than early pregnancy—high hemoglobin is a danger signal for adverse outcomes, while routine iron supplementation is unnecessary in well-nourished populations but essential in areas of high anemia prevalence. 3
Third Trimester (28 weeks to delivery)
Fetal Surveillance
Antepartum fetal surveillance (nonstress testing, amniotic fluid assessment, biophysical profile) should begin at 32-34 weeks for high-risk pregnancies including those with pregestational diabetes. 2, 1
Monthly fetal growth monitoring ultrasounds from viability are recommended for certain high-risk conditions. 2
Preeclampsia Monitoring
Vigilant screening for preeclampsia signs is essential, particularly in women with identified risk factors who should already be on aspirin prophylaxis. 1
Delivery Planning
Ultrasound for fetal growth assessment should guide delivery planning. 2 Consider cesarean delivery if estimated fetal weight exceeds 4500 grams in diabetic pregnancies. 2
Delivery timing for women with pregestational diabetes: if good glycemic control without vascular complications, deliver at 39 0/7 to 39 6/7 weeks; if poor glycemic control or complications present, individualized earlier timing may be necessary. 2
Common Pitfalls and Critical Considerations
The most common error is failing to identify women at high risk for preeclampsia who would benefit from early aspirin prophylaxis—this intervention must be initiated before 16 weeks to be effective. 1
Preconception care cannot be replaced by early prenatal care—by the time of the first prenatal visit, organogenesis has begun and placental development is already underway, making it too late to prevent certain complications. 2 Approximately half of pregnancies in the United States are unintended, making routine preconception counseling at all well-woman visits essential. 2
Routine iron supplementation in well-nourished populations is unnecessary and potentially harmful—high hemoglobin levels late in pregnancy are associated with adverse outcomes. 3
Urine culture or dipstick for leucocyte esterase and nitrite with treatment of positive cases reduces pyelonephritis risk and is cost-effective. 3
Fewer routine visits for low-risk women do not increase pregnancy risk but may lessen patient satisfaction—the focus should be on content and quality of visits rather than quantity. 3
Mental health screening should occur throughout pregnancy, not just at initial visit, as perinatal mood disorders can develop at any time. 2