What is the preferred treatment for chronic hypertension (HTN) in pregnancy, labetalol or nifedipine?

Treatment of Chronic Hypertension in Pregnancy: Labetalol vs. Nifedipine

Both extended-release nifedipine and labetalol are equally effective first-line antihypertensive medications for chronic hypertension in pregnancy, with no compelling data supporting the use of one agent over the other. 1

First-Line Medication Options

Extended-Release Nifedipine

• Advantages:
  • Once-daily dosing improves patient adherence 1
  • More effective than methyldopa for prevention of severe hypertension 1
  • Recent research suggests it may have higher rates of blood pressure control compared to methyldopa (84% vs 76%) 2

Labetalol

• Advantages:
  • Well-established safety profile 3
  • Alternative for patients who experience side effects from nifedipine (headaches, tachycardia, edema) 1
  • Can be used in combination with nifedipine for uncontrolled BP 1
• Limitations:
  • May require TID or QID dosing due to accelerated drug metabolism during pregnancy 1
  • Contraindicated in patients with reactive airway disease/asthma 1, 3
  • Potential risks include fetal growth restriction, fetal bradycardia, and hypoglycemia, though these risks are minimal 1

Comparative Effectiveness and Safety

A recent 2025 study comparing labetalol and nifedipine for chronic hypertension in pregnancy found no significant differences in:

• Effectiveness outcomes (severe preeclampsia/eclampsia, medically indicated preterm birth, placental abruption, or stillbirth) 4
• Safety outcomes (small for gestational age infants) 4

Treatment Approach

1. Initial BP Target: Lower BP below 140/90 mmHg but not below 80 mmHg for diastolic BP 1

2. Medication Selection:

   • For patients prioritizing convenience: Start with extended-release nifedipine (once-daily dosing)
   • For patients with headaches, tachycardia, or edema: Consider labetalol
   • For patients with asthma/reactive airway disease: Avoid labetalol, use nifedipine

3. Dosing and Monitoring:

   • Monitor for adequate BP control
   • If BP remains uncontrolled, consider combination therapy with both agents 1
   • Monitor fetal heart rate during uptitration of labetalol, especially when doses exceed 800 mg/24h 3

4. Important Contraindications:

   • ACE inhibitors, angiotensin receptor blockers, mineralocorticoid receptor antagonists, and direct renin inhibitors are contraindicated in pregnancy 1, 3
   • Avoid atenolol due to risk of fetal growth restriction 1

Clinical Pearls

• A post hoc analysis of the CHAP trial found no difference in maternal or neonatal outcomes between patients taking labetalol compared with nifedipine 1
• Methyldopa is another first-line option but has fallen out of favor in high-income countries due to its side effect profile (peripheral edema, dry mouth, lightheadedness, drowsiness, mood effects) 1
• For severe hypertension (≥160/110 mmHg), immediate treatment is required, with IV labetalol or extended-release nifedipine as preferred options 3
• Consider testing for orthostatic hypotension before starting or intensifying BP-lowering medication 1

In summary, both extended-release nifedipine and labetalol are appropriate first-line choices for chronic hypertension in pregnancy, with selection based primarily on patient-specific factors such as comorbidities, side effect profile, and dosing convenience.