What is the recommended management for a 37‑week pregnant woman with severe hypertension and a non‑reassuring (category II/III) fetal heart rate tracing?

Management of a 37-Week Pregnant Woman with Severe Hypertension and Category II Fetal Heart Rate Tracing

This patient requires immediate delivery after maternal stabilization with magnesium sulfate and aggressive blood pressure control. At 37 weeks gestation with preeclampsia (presumed given elevated blood pressures) and a non-reassuring fetal heart rate tracing, both maternal and fetal indications mandate delivery. 1, 2

Immediate Stabilization (Before Delivery)

Blood Pressure Management

• Treat severe hypertension (≥160/110 mmHg) urgently within 30-60 minutes to prevent maternal stroke and cerebral hemorrhage 1, 2
• First-line IV antihypertensive options:
  • IV labetalol: 20mg bolus, then 40mg after 10 minutes, then 80mg every 10 minutes (maximum 220mg) 1, 3
  • IV hydralazine: alternative if labetalol unavailable 1
  • Oral nifedipine (immediate-release): acceptable alternative 1
• Target blood pressure: systolic 110-140 mmHg and diastolic ~85 mmHg (at minimum <160/105 mmHg) 1, 3

Seizure Prophylaxis

• Administer magnesium sulfate immediately for all women with severe hypertension and preeclampsia 1, 4
• Loading dose: 4-5 grams IV over 5-20 minutes 4, 3
• Maintenance: 1-2 grams/hour continuous IV infusion 4, 3
• Continue for minimum 24 hours postpartum as eclamptic seizures may develop for the first time after delivery 4, 3

Critical pitfall to avoid: Never combine magnesium sulfate with IV or sublingual nifedipine—this causes severe myocardial depression and precipitous hypotension 4, 3

Delivery Decision

Absolute Indications Present

This patient has two absolute indications for immediate delivery:

1. Gestational age ≥37 weeks with preeclampsia (delivery mandatory regardless of other factors) 1, 2
2. Non-reassuring fetal status (category II tracing qualifies as concerning fetal status requiring delivery) 1, 2

Mode of Delivery

• Attempt vaginal delivery unless standard obstetric contraindications exist 2, 3
• Cesarean section is indicated ONLY for:
  • Standard obstetric indications (malpresentation, prior classical cesarean, placenta previa) 2
  • Maternal or fetal deterioration requiring immediate delivery when vaginal delivery cannot be accomplished expeditiously 2
  • Evidence of placental insufficiency with fetal compromise requiring immediate delivery 2

Critical pitfall: Do not perform cesarean section solely because blood pressure is difficult to control—this is an indication for delivery, not specifically for cesarean delivery 2

Critical Monitoring During Stabilization

Maternal Monitoring

• Continuous blood pressure monitoring until stable 1, 3
• Hourly urine output via Foley catheter (target ≥100 mL/4 hours or >35 mL/hour) 3
• Deep tendon reflexes before each magnesium dose to detect toxicity 3
• Respiratory rate monitoring (magnesium toxicity causes respiratory depression at rates <12/min) 4, 3
• Oxygen saturation (maintain >90%) 2, 3
• Assess for severe headache, visual scotomata, epigastric pain (signs of imminent eclampsia or HELLP syndrome) 1, 3

Laboratory Assessment

• Immediate labs: complete blood count (platelets), liver transaminases, creatinine, uric acid 1
• Assess for HELLP syndrome: hemolysis, elevated liver enzymes, low platelets 3, 5

Fetal Monitoring

• Continuous fetal heart rate monitoring until delivery 3
• Ultrasound assessment: fetal biometry, amniotic fluid, umbilical artery Doppler 1

Anesthesia Considerations for Delivery

• Regional anesthesia (epidural/spinal) is preferred if patient is conscious, cooperative, and has no coagulopathy 6
• Check platelet count before regional anesthesia—thrombocytopenia is a contraindication 6
• General anesthesia may be necessary if patient has eclamptic seizures, severe coagulopathy, or requires emergent delivery 6
• Maintain left lateral positioning during cesarean section to optimize uteroplacental perfusion 6

Medications to Avoid

• ACE inhibitors, ARBs, direct renin inhibitors: absolutely contraindicated due to severe fetotoxicity 3
• Diuretics: contraindicated as they further reduce plasma volume 3
• Sublingual nifedipine with magnesium sulfate: risk of uncontrolled hypotension 3
• Sodium nitroprusside: only as last resort due to risk of fetal cyanide poisoning 3

Post-Delivery Management

• Continue magnesium sulfate for 24 hours postpartum 4, 3
• Monitor blood pressure at least every 4 hours while awake for minimum 3 days postpartum 3
• Switch methyldopa to alternative antihypertensive if used during pregnancy 1
• Hypertension may worsen between days 3-6 postpartum—maintain vigilance 1