What are the guidelines for using propranolol (beta-blocker) during pregnancy?

Propranolol Use During Pregnancy

Propranolol should be used with caution during pregnancy, with selective β1-blockers like metoprolol preferred as first-line agents when beta-blockade is required during pregnancy. 1

Safety Classification and Concerns

• Propranolol is classified as FDA Pregnancy Category C, indicating potential risks that must be weighed against benefits 2
• Key concerns with propranolol use during pregnancy include:
  • Intrauterine growth restriction (IUGR) - most significant concern, particularly with first-trimester use 1, 3
  • Neonatal complications that may occur include:
    • Hypoglycemia
    • Respiratory depression
    • Bradycardia
    • Hyperbilirubinemia

Clinical Recommendations

Timing Considerations

• First trimester: Avoid propranolol whenever possible 1, 2
• Second and third trimesters: Can be used with appropriate monitoring

Indications with Strong Support

• For long-term management of idiopathic sustained ventricular tachycardia (VT), propranolol is recommended (Class I recommendation) 4
• For long-term management of congenital long QT syndrome, beta-blockers are recommended during pregnancy and postpartum 4

Monitoring Requirements

• Regular ultrasound monitoring of fetal growth is essential when propranolol is used during pregnancy 1
• Facilities for monitoring neonates at birth should be available due to potential for:
  • Bradycardia
  • Hypoglycemia
  • Respiratory depression 2

Alternative Beta-Blockers

• Selective β1-blockers (e.g., metoprolol) are preferred over propranolol during pregnancy 1
• These agents may interfere less with peripheral vasodilation and uterine relaxation
• Atenolol should NOT be used for any arrhythmia during pregnancy (Class III recommendation) 4

Dosing Considerations

• Use the lowest effective dose of propranolol when necessary 1
• Transplacental transfer of propranolol occurs, with neonatal plasma levels potentially increasing after birth 5
• Pregnancy may alter drug effect without changing pharmacokinetics, potentially requiring dose adjustments 6

Labor and Delivery Considerations

• If propranolol is continued until delivery:
  • Monitor neonate for hypoglycemia, bradycardia, and respiratory depression 5, 7
  • Consider regional anesthesia over general anesthesia if cesarean delivery is required 8
  • Continuous ECG and central venous pressure monitoring is recommended if general anesthesia is necessary 8

Common Pitfalls

• Failing to monitor fetal growth regularly when propranolol is used
• Using atenolol instead of other beta-blockers during pregnancy
• Not having facilities available to monitor neonates after delivery
• Using high doses when lower doses might be effective
• Discontinuing necessary treatment when benefits outweigh risks

By following these guidelines and maintaining appropriate monitoring, propranolol can be used safely in pregnant women when clinically indicated, particularly for arrhythmia management when other options are not suitable or effective.