Is Propranolol (beta blocker) safe to take during pregnancy?

Propranolol Use During Pregnancy

Propranolol can be used during pregnancy but should be avoided in the first trimester if possible, and requires careful monitoring due to potential risks of fetal growth restriction and neonatal complications. 1, 2

Safety Profile and Recommendations

Propranolol is classified as a pregnancy Category C medication by the FDA, indicating that:

• It is generally considered safe for use during pregnancy but with some important caveats 1
• It has a Class IIa recommendation (should be considered) for management of supraventricular tachycardia during pregnancy 1
• It should be avoided during the first trimester whenever possible 1

Potential Risks to Consider

Maternal Considerations

• Propranolol's pharmacodynamic effects may be enhanced during pregnancy, requiring potential dose adjustments 3
• Monitoring is needed as pregnancy can alter drug effects even without pharmacokinetic changes 3

Fetal and Neonatal Risks

1. Intrauterine Growth Restriction:

   • Most significant concern with propranolol use during pregnancy 1, 2, 4
   • More pronounced when used during first trimester 1

2. Neonatal complications that may occur but are not invariable:

   • Bradycardia in neonates whose mothers received propranolol at parturition 2, 5
   • Hypoglycemia 2, 5, 6
   • Respiratory depression 2, 5, 6

Clinical Decision Algorithm

1. First-line approach for pregnant women requiring beta-blockade:

   • Use selective β1-blockers like metoprolol if possible (preferred over propranolol) 1
   • These may interfere less with peripheral vasodilation and uterine relaxation 1

2. If propranolol is necessary:

   • Avoid during first trimester if possible 1
   • Use lowest effective dose 1
   • Monitor fetal growth regularly via ultrasound 4
   • Ensure facilities for monitoring infants at birth are available 2

3. For acute conversion of SVT during pregnancy:

   • Vagal maneuvers and adenosine are first-line options 1
   • Propranolol can be considered if these fail 1

4. For long-term management during pregnancy:

   • Digoxin or metoprolol are first-line agents 1
   • Propranolol is a second-line option 1

Important Monitoring Considerations

• Regular fetal growth monitoring throughout pregnancy
• Blood glucose monitoring in the neonate after delivery
• Cardiac monitoring for bradycardia in the neonate
• Respiratory monitoring in the immediate postpartum period

Key Practice Points

• Beta-blockers with selective β1 properties (like metoprolol) are theoretically preferable to propranolol during pregnancy 1
• Prospective randomized studies have failed to demonstrate a higher incidence of complications with beta-blockers compared to placebo, but caution is still warranted 1
• Propranolol is excreted in human milk, so caution should be exercised during breastfeeding 2
• The benefits of propranolol treatment must clearly outweigh the potential risks to justify its use during pregnancy 2