What are the recommendations for managing a 36-year-old female, gravida 4, para 2, at 31 weeks gestation, with preeclampsia (PEC), currently on Nifedipine (generic name: Nifedipine) 30 mg daily and Labetalol (generic name: Labetalol) 300 mg orally every 8 hours, with an average blood pressure of 140/80 mmHg, and a plan to increase Nifedipine to 20 mg every 12 hours?

Management of Preeclampsia at 31 Weeks Gestation

In addition to increasing nifedipine to 20mg Q12h, magnesium sulfate should be initiated for seizure prophylaxis with a loading dose of 4g IV over 5 minutes followed by a maintenance dose of 1g/hour IV infusion, continuing for at least 24 hours postpartum. 1

Current Assessment and Management

• 36-year-old G4P2103 at 31 weeks gestation with preeclampsia
• Current medications: Nifedipine 30mg daily and Labetalol 300mg PO Q8h
• Average BP: 140/80 mmHg
• Plan to increase Nifedipine to 20mg Q12h

Additional Recommendations

1. Seizure Prophylaxis

• Initiate magnesium sulfate for convulsion prophylaxis 2, 1
• Loading dose: 4g IV over 5 minutes
• Maintenance dose: 1g/hour IV infusion
• Continue for at least 24 hours postpartum
• Alternative regimen if IV access limited: 5g IM into each buttock, then 5g IM every 4 hours 1

2. Blood Pressure Monitoring

• Target diastolic BP of 85 mmHg and systolic BP <160 mmHg 2
• Reduce or cease antihypertensive drugs if diastolic BP falls <80 mmHg 2
• Monitor BP closely during medication adjustments
• Consider continuous BP monitoring if control is difficult 1

3. Maternal Surveillance

• Perform twice weekly blood tests: hemoglobin, platelet count, liver transaminases, creatinine, and uric acid 2
• Clinical assessment for signs of worsening preeclampsia (clonus, headache, visual disturbances)
• Monitor for magnesium toxicity: respiratory rate, deep tendon reflexes, urine output 1
• Assess for pulmonary edema

4. Fetal Monitoring

• Ultrasound assessment of fetal biometry, amniotic fluid, and umbilical artery Doppler 2
• Regular fetal heart rate monitoring, especially during labetalol dose adjustments 1
• Plan for antenatal corticosteroids if delivery anticipated before 34 weeks

5. Delivery Planning

• At 31 weeks, expectant management is appropriate if maternal and fetal conditions remain stable 2
• Consider delivery if any of the following develop:
  • Repeated episodes of severe hypertension despite treatment
  • Progressive thrombocytopenia
  • Progressive abnormal renal or liver function
  • Pulmonary edema
  • Neurological features (severe headache, visual scotomata)
  • Non-reassuring fetal status 2

6. Medication Considerations

• Avoid concurrent use of nifedipine with magnesium sulfate without careful monitoring due to risk of precipitous BP drop 1, 3
• Monitor for side effects of labetalol, including bronchospasm and maternal bradycardia 4
• Avoid atenolol due to risk of fetal growth restriction 1

Important Precautions

• Consider hospitalization if BP rises to ≥170/110 mmHg, which is considered an emergency 2, 1
• Do not attempt to diagnose mild versus severe preeclampsia as all cases may rapidly progress to emergencies 2
• Be aware that grapefruit juice can increase nifedipine levels and should be avoided 3
• Recognize that preeclampsia at 31 weeks carries significant risks and requires close monitoring even if BP appears controlled

Follow-up Plan

• Reassess BP response to increased nifedipine dosing within 24 hours
• Daily clinical assessment for signs of worsening preeclampsia
• Weekly ultrasound for fetal growth and well-being
• Plan for delivery by 37 weeks if preeclampsia remains stable 2