///2015 Abstract Details
2015 Abstract Details2019-08-02T16:54:43-06:00

Late Pregnancy Exposure to Beta Blockers and the Risks of Neonatal Hypoglycemia and Bradycardia

Abstract Number: T-12
Abstract Type: Original Research

Brian T Bateman MD, MSc1 ; Krista F Huybrechts MS, PhD2; Rishi Desai PhD3; Elisabetta Patorno MD, DrPH4; Sonia Hernandez-Diaz MD, DrPH5

Introduction: Beta blockers are widely used in the treatment of hypertensive disorders during pregnancy. These medications cross the placenta and may cause physiologic changes in neonates exposed in utero. Some prior studies suggest an association between late pregnancy beta blocker exposure and the risks of neonatal hypoglycemia and bradycardia, but the magnitude of these risks and the question of whether they extend to the alpha-beta blocker labetalol are poorly defined.

Methods: We used a cohort of 2,292,116 completed pregnancies linked to liveborn infants of women enrolled in Medicaid from 2003 to 2007. We examined the risk of neonatal hypoglycemia and neonatal bradycardia associated with maternal exposure to beta blockers at the time of delivery, defined by a dispensed outpatient prescription whose days supply overlaps with the date of delivery. The reference group consisted of pregnancies not exposed to beta blockers at the time of delivery. Propensity score matching (1:3 fixed ratio) was used to control for potential confounders including maternal demographics, obstetric and medical conditions, and exposure to other medications.

Results: There were 10,585 (0.5%) pregnancies exposed to beta blockers at the time of delivery. The risk of neonatal hypoglycemia was 4.3% in the beta blocker exposed vs 1.2% in the unexposed; the risk of neonatal bradycardia was 1.6% in the exposed vs 0.5% in the unexposed. After controlling for confounders, risk remained elevated for both neonatal hypoglycemia and bradycardia among exposed pregnancies vs unexposed (adjusted odd ratio (aOR) 1.7, 95% CI 1.5 to 1.9 and aOR 1.3, 95% CI 1.1 to 1.6, respectively). Risks were similarly elevated for those exposed to labetalol vs unexposed (aOR 1.8, 95% CI 1.6 to 2.0 for hypoglycemia and 1.3, 95% CI 1.1 to 1.7 for bradycardia). Results were similar across multiple sensitivity analyses.

Conclusion: Our findings suggest that neonates born to mothers exposed to beta blockers in late pregnancy, including labetalol, are at elevated risk for neonatal hypoglycemia and bradycardia. Exposed neonates may benefit from monitoring for these conditions.

SOAP 2015