What is the recommended treatment for chronic hypertension in pregnancy?

Treatment of Chronic Hypertension in Pregnancy

First-line medications for treating chronic hypertension during pregnancy include methyldopa, labetalol, and nifedipine, with treatment recommended when blood pressure is ≥140/90 mmHg. 1

First-Line Medication Options

Preferred Medications

• Methyldopa:

  • Traditional first-line agent with extensive safety data
  • Dosing: Start with 250mg BID-TID, can increase to 1-1.5g daily 1
  • Safe during all trimesters with long-term follow-up studies showing no adverse effects on child development 2

• Labetalol:

  • Effective alternative with rapid onset
  • Dosing: Start with 100-200mg BID, can increase as needed 1
  • Caution in patients with asthma or reactive airway disease 1

• Nifedipine (extended-release):

  • Calcium channel blocker with good efficacy
  • Dosing: 10-30mg daily or BID 1
  • Recent evidence suggests superior efficacy compared to other agents 3, 4

Blood Pressure Targets

• Target blood pressure should be maintained below 140/90 mmHg 1
• Diastolic BP should not be reduced below 80 mmHg to maintain uteroplacental perfusion 1
• The CHAP trial demonstrated that treating mild chronic hypertension in pregnancy to a goal of <140/90 mmHg reduced the risk of adverse maternal and fetal outcomes 5

Medications to Avoid

• Absolutely contraindicated:

  • ACE inhibitors
  • Angiotensin II receptor blockers (ARBs)
  • Direct renin inhibitors
  • Mineralocorticoid receptor antagonists

  These medications can cause significant teratogenic effects and fetal harm 6, 1

• Use with caution:

  • Atenolol: Associated with fetal growth restriction 1
  • Diuretics: Not recommended for blood pressure control during pregnancy 1

Management Algorithm

1. Initial Assessment:

   • Confirm chronic hypertension diagnosis (present before pregnancy or before 20 weeks gestation) 6
   • Evaluate for end-organ damage and baseline labs

2. Medication Selection:

   • For new diagnosis or medication transition:
     • First choice: Methyldopa (extensive safety data) or Labetalol
     • Alternative: Extended-release nifedipine
   • For women already on antihypertensives:
     • Switch from contraindicated medications (ACE inhibitors, ARBs) to pregnancy-safe options immediately 6, 1

3. Monitoring:

   • Regular BP checks (at least weekly in early pregnancy)
   • Monitor for development of superimposed preeclampsia
   • Regular assessment of fetal growth and well-being
   • Laboratory monitoring: CBC, renal function, liver enzymes, urinalysis 6, 1

4. Dose Adjustments:

   • Increase medication dose if BP consistently >140/90 mmHg
   • Add second agent if maximum dose of first medication is insufficient
   • Common combination: Methyldopa + Nifedipine or Labetalol + Nifedipine

Special Considerations

Severe Hypertension

• For BP ≥160/110 mmHg, urgent treatment is required 6, 1
• IV labetalol, IV hydralazine, or oral nifedipine are appropriate options
• Hospitalization should be considered 1

Postpartum Management

• Hypertension may worsen 3-6 days postpartum 1
• Continue antihypertensive medications after delivery
• Switch from methyldopa to an alternative agent in the postpartum period due to increased risk of depression 1
• Long-term follow-up is recommended as women with chronic hypertension during pregnancy have increased lifetime cardiovascular risk 6

Evidence Quality and Considerations

The most recent and comprehensive guidelines from the European Society of Cardiology, American Heart Association, and International Society for the Study of Hypertension in Pregnancy (ISSHP) consistently recommend methyldopa, labetalol, and nifedipine as first-line agents 6, 1.

Recent research from the CHAP trial provides strong evidence that treating chronic hypertension in pregnancy to a goal of <140/90 mmHg improves maternal and fetal outcomes 5, supporting a more aggressive treatment approach than previously recommended.

A 2019 network meta-analysis found that nifedipine may be more effective than hydralazine for treating severe hypertension in pregnancy, with a favorable safety profile 4, suggesting it could be preferred when rapid control is needed.