Maternal Bradycardia Associated with Betamethasone Administration During Pregnancy

BACKGROUND: Maternal risks of betamethasone have been rarely reported. CASE: At 36 weeks' gestation, a previously healthy 23-year-old gravida with fetal intrauterine growth restriction was admitted to the hospital for steroid administration. Twenty-six hours after the first dose of betamethasone, a maternal bradycardia was initially noted and eventually nadired at 41 beats per minute. Consultation with the cardio-electrophysiology service revealed no other apparent etiologies for the sinus bradycardia. Due to the asymptomatic nature of the maternal bradycardia, pharmacologic interventions were not recommended. With observation alone, a normal maternal heart rate returned by forty-nine hours after the original betamethasone injection. The patient subsequently had an uneventful intrapartum course. CONCLUSION: Maternal bradycardia can be associated with antenatal betamethasone administration. Due to the transient nature of this side effect, expectant management is recommended as the treatment option for asymptomatic patients.