Abstract 19275: Association Between Exposure to Different Beta-Blocker Subtypes During Pregnancy and the Risk of Low Birth Weight
Introduction: Beta-blockers are one of the most commonly prescribed classes of cardiovascular medications during pregnancy. Previous studies reported an association between beta-blocker treatment and low birth weight. Whether some beta blocker subtypes may be associated with higher risk is not known.
Methods: This is a retrospective cohort study of pregnant women in the Kaiser Permanente Southern California Medical System between Jan 1, 2003 to Sept 30, 2015. Pregnant women exposed to beta-blockers were identified using pharmacy dispensed records. We limited our analyses to singleton live births. Odds ratios of low birth weight (<2500 g) were estimated using logistic regression models adjusted for maternal age, gestational age, ethnicity, maternal body mass index, weight gain during pregnancy, and maternal comorbidities.
Results: We identified 4,753 women exposed to atenolol (n=628), labetalol (n=3321), metoprolol (n=322), or propranolol (n=482) during their pregnancy. Women with a history of hypertension but not exposed to any beta-blockers were used as control (n=25,531). Mean birth weight and % low birth weight (<2500 g) were 3081 +/- 711 g and 17.2% for atenolol, 2945 +/- 818 g and 24.8% for labetalol, 3179 +/- 673 g and 12.7% for metoprolol, 3304 +/- 628 g and 6.9% for propranolol, and 3261 +/- 667 and 10.4% for controls. When compared to controls, exposure to atenolol and labetalol were associated with increased risk of low birth weight (atenolol: adjusted OR 1.7, 95% CI 1.1-2.7; labetalol: adjusted OR 1.8, 95% CI 1.5-2.1). Risk of low birth weight associated with metoprolol or propranolol were not significantly different from the control group (metoprolol: adjusted OR 1.1, 95% CI 0.6-2.1; propranolol: adjusted OR 0.9, 95% CI 0.5-1.6). Odds ratio are shown in the figure.
Conclusions: In this cohort of pregnant women exposed to beta-blockers, exposure to atenolol or labetalol was associated with higher risk of low birth weight.
Author Disclosures: J. Nguyen: None. A. Ng: None. L. Duan: None. A. Shen: None. M. Lee: None.
- © 2016 by American Heart Association, Inc.