Obstetrics focuses on caring for pregnant women and ensuring optimal outcomes for both mother and baby. Effective antenatal care involves risk assessment, monitoring fetal development, and recognizing complications early. This comprehensive guide covers essential antenatal care protocols, screening tests, and common pregnancy complications that every medical student and clinician should understand.

Pregnant woman ultrasound

Antenatal Care Schedule

Booking Visit (8-12 weeks)

History:

  • Last menstrual period (LMP), calculate expected date of delivery (EDD)
  • Previous obstetric history (gravida, para, abortions)
  • Medical history (diabetes, hypertension, thyroid disorders)
  • Family history (genetic disorders, twins)
  • Social history (smoking, alcohol, drugs)

Examination:

  • Height, weight, BMI calculation
  • Blood pressure baseline
  • General and systemic examination

Investigations:

  • Blood group and Rh typing
  • Complete blood count (hemoglobin, platelets)
  • Blood glucose (fasting/random)
  • VDRL/RPR (syphilis screening)
  • HIV, HBsAg, HCV screening
  • Urine routine and culture
  • TSH (thyroid function)
  • First trimester ultrasound (dating, nuchal translucency)

For detailed examination techniques, see our Clinical Examination Guide.

Routine Antenatal Visits

Visit Schedule:

  • Every 4 weeks until 28 weeks
  • Every 2 weeks from 28-36 weeks
  • Weekly from 36 weeks until delivery

At Each Visit:

  • Blood pressure monitoring
  • Urine dipstick (protein, glucose)
  • Symphysis-fundal height measurement (after 24 weeks)
  • Fetal heart rate auscultation
  • Assess fetal movements
  • Check for edema

Antenatal Screening Tests

Medical laboratory testing

First Trimester (11-13 weeks)

Combined Screening:

  • Nuchal translucency (NT) on ultrasound
  • Serum markers: β-hCG, PAPP-A
  • Screens for Down syndrome (trisomy 21), trisomy 18, trisomy 13

Second Trimester (15-20 weeks)

Quadruple Test:

  • AFP, β-hCG, uE3, Inhibin A
  • Screens for neural tube defects and chromosomal abnormalities

Anomaly Scan (18-22 weeks):

  • Detailed fetal anatomy survey
  • Four-chamber heart view
  • Neural tube defects, abdominal wall defects
  • Placental location

Third Trimester

Glucose Tolerance Test (24-28 weeks):

  • Screen for gestational diabetes
  • 75g OGTT or 100g OGTT

Growth Scans:

  • If risk factors for IUGR or macrosomia
  • Amniotic fluid volume assessment
  • Doppler studies if indicated

Learn more about prenatal testing at ACOG Guidelines.

Common Pregnancy Complications

Hypertensive Disorders

Gestational Hypertension:

  • BP ≥140/90 after 20 weeks without proteinuria
  • Management: Monitoring, antihypertensives if severe

Preeclampsia:

  • BP ≥140/90 + proteinuria (≥300 mg/24h) after 20 weeks
  • Symptoms: Headache, visual disturbances, epigastric pain, edema
  • Severe features: BP ≥160/110, organ dysfunction
  • Management: Delivery is definitive cure, magnesium sulfate for seizure prophylaxis

Eclampsia:

  • Preeclampsia + seizures
  • Medical emergency
  • Treatment: Magnesium sulfate, control BP, deliver

Gestational Diabetes

  • Glucose intolerance first recognized in pregnancy
  • Risk factors: Obesity, family history, previous GDM, PCOS
  • Complications: Macrosomia, polyhydramnios, neonatal hypoglycemia
  • Management: Diet, exercise, insulin if needed
  • Postpartum: Screen for diabetes at 6 weeks
Pregnant woman healthcare

Anemia in Pregnancy

Iron Deficiency Anemia:

  • Most common (Hb <11 g/dL in 1st/3rd trimester, <10.5 in 2nd)
  • Symptoms: Fatigue, pallor, dyspnea
  • Treatment: Oral iron supplementation, IV iron if severe/intolerant
  • Prophylaxis: All pregnant women should receive iron and folic acid

Antepartum Hemorrhage

Placenta Previa:

  • Placenta covers internal cervical os
  • Painless vaginal bleeding (typically 3rd trimester)
  • Diagnosis: Ultrasound (NEVER do vaginal examination)
  • Management: Expectant if stable, cesarean delivery

Placental Abruption:

  • Premature separation of placenta
  • Painful bleeding, uterine tenderness, fetal distress
  • Risk factors: Hypertension, trauma, cocaine use
  • Management: Immediate delivery if severe

Intrauterine Growth Restriction (IUGR)

  • Fetal weight <10th percentile for gestational age
  • Causes: Placental insufficiency, maternal hypertension, infections
  • Monitoring: Serial growth scans, Doppler studies
  • Management: Deliver when risks of prematurity < risks of continued pregnancy

Preterm Labor

  • Labor before 37 weeks gestation
  • Risk factors: Previous preterm birth, multiple pregnancy, infection
  • Management: Tocolytics (short-term), corticosteroids for fetal lung maturity
  • Magnesium sulfate for neuroprotection if <32 weeks

Fetal Monitoring

Kick Counts

  • Maternal assessment of fetal movements
  • ≥10 movements in 2 hours is reassuring
  • Decreased movements warrant immediate evaluation

Non-Stress Test (NST)

  • Monitors fetal heart rate and movements
  • Reactive (normal): ≥2 accelerations in 20 minutes
  • Non-reactive: May need further evaluation (biophysical profile, contraction stress test)

Biophysical Profile

  • NST + ultrasound assessment (fetal breathing, movements, tone, amniotic fluid)
  • Score 8-10: Normal
  • Score ≤6: Consider delivery

Medications in Pregnancy

Safe Medications:

  • Acetaminophen (paracetamol)
  • Penicillins, cephalosporins
  • Methyldopa, labetalol (for hypertension)
  • Insulin

Avoid:

  • ACE inhibitors, ARBs (teratogenic)
  • Warfarin (teratogenic - use heparin instead)
  • Tetracyclines (teeth/bone effects)
  • NSAIDs in 3rd trimester (premature ductus closure)
  • Isotretinoin (severe teratogen)

For drug safety, see our Pharmacology Guide.

External Resources

Conclusion

Effective antenatal care requires systematic monitoring, appropriate screening, and early recognition of complications. Understanding normal pregnancy physiology and common complications enables better patient care and outcomes. Practice with our Question Bank and explore more obstetrics topics in our blog section.