Which is safer for managing hypertension in pregnancy, propranolol (beta blocker) or labetalol (alpha/beta blocker)?

Labetalol is Safer than Propranolol for Managing Hypertension in Pregnancy

Labetalol is the preferred beta-blocker for managing hypertension during pregnancy compared to propranolol due to its better safety profile and fewer adverse fetal effects. 1

Comparison of Safety Profiles

Labetalol (Alpha/Beta Blocker)

• Recommended as a first-line agent for hypertension management during pregnancy by multiple guidelines 1
• Has combined alpha-1 and non-selective beta-blocking properties, providing more balanced blood pressure control 1
• Associated with minimal risk of fetal growth restriction, with no reports of teratogenicity 1
• Effectively controls blood pressure in pregnancy, with success rates of up to 82% 2
• Considered safe and effective for intravenous treatment of severe pre-eclampsia 1

Propranolol (Non-selective Beta Blocker)

• Not specifically recommended in pregnancy guidelines for hypertension management 1
• As a non-selective beta blocker, propranolol carries higher risks of:
  • Fetal growth restriction 2
  • Neonatal bradycardia 1
  • Neonatal hypoglycemia 1
• The non-selective beta-blocking properties without alpha blockade may lead to unopposed alpha-mediated vasoconstriction 1

Evidence Supporting Labetalol's Superior Safety

• A comparative study showed significantly higher birth weights with labetalol (3280 ± 555g) compared to atenolol (another beta-blocker) (2750 ± 630g), suggesting labetalol better preserves fetal growth 2
• Multiple guidelines consistently recommend labetalol as one of the first-line agents for hypertension in pregnancy 1
• A 2025 study comparing labetalol with nifedipine found similar safety outcomes regarding small-for-gestational-age infants (adjusted RR: 0.98,95% CI: 0.82-1.16), confirming labetalol's favorable safety profile 3

Clinical Recommendations for Using Labetalol in Pregnancy

• Starting dose typically 100-200 mg twice daily, can be titrated up to 1200 mg daily in divided doses 4
• May need more frequent dosing (TID or QID) due to accelerated drug metabolism during pregnancy 1
• For severe hypertension requiring IV treatment, start with 10-20 mg IV, can be titrated up to 300 mg 1
• Monitor for potential side effects including:
  • Bronchospasm (use with caution in patients with asthma) 1
  • Bradycardia 1
  • Postural hypotension 1

Important Considerations and Precautions

• Both medications cross the placenta, but labetalol appears to have fewer adverse fetal effects 2
• Labetalol is contraindicated in patients with:
  • Second or third-degree AV block 1
  • Maternal systolic heart failure 1
  • Use with caution in women with asthma 1
• The goal of antihypertensive treatment during pregnancy is to prevent severe hypertension while allowing the fetus more time to mature 1
• Target blood pressure during treatment of severe hypertension should be SBP 140-150 mmHg and DBP 90-100 mmHg 1

Conclusion

For managing hypertension in pregnancy, labetalol is clearly the safer choice compared to propranolol based on current guidelines and available evidence. Labetalol's combined alpha and beta-blocking properties provide effective blood pressure control with fewer adverse fetal effects, particularly regarding fetal growth restriction 1, 2.