Beta-Blockers in Pregnancy and Congenital Malformation Risk
What is the risk of major congenital malformations associated with use of beta-blockers during the first trimester?
Data from the US Medicaid database and registries in the five Nordic countries were analyzed for pregnant women with a diagnosis of hypertension exposed to beta-blockers during the first trimester. Outcomes assessed among their offspring were any major congenital malformation, cardiac malformations, cleft lip or palate, and central nervous system malformations. Potential confounders were controlled by propensity score stratification.
Women with hypertension exposed to beta-blocker therapy in the first trimester included 682/3,577 (19.1%) women in the Nordic cohort and 1,668/14,900 (11.2%) women in the US cohort. The pooled adjusted relative risk (RR) and risk difference per 1,000 persons exposed associated with beta-blockers for any major malformation were 1.07 (95% confidence interval [CI], 0.89-1.30) and 3.0 (CI, -6.6 to 12.6), respectively; for any cardiac malformation, 1.12 (CI, 0.83-1.51) and 2.1 (CI, -4.3 to 8.4), respectively; for cleft lip or palate, 1.97 (CI, 0.74-5.25) and 1.0 (CI -0.9 to 3.0); for central nervous system malformations, 1.37 (CI 0.58-3.25) and 1.0 (CI, -2.0 to 4.0), respectively. The analysis was limited to live births and exposure was based on dispensed medications.
Maternal use of beta-blockers in the first trimester is not associated with an increased risk for congenital malformations.
Beta-blockers are a first-line medication for hypertension during pregnancy and are also used during pregnancy for various other maternal cardiac conditions. This large study provides further reassurance that the use of beta-blocker medication during the first trimester is not associated with an increased risk of congenital malformations. This conclusion is in agreement with prior studies that have controlled for the presence of hypertension as a confounder, since maternal hypertension itself is associated with increased risk for congenital malformations. While labetalol is useful for the treatment of hypertension, metoprolol is the most commonly used beta-blocker for arrhythmias, cardiomyopathies, and aortopathies. Not addressed in this study, but also important to consider, is the association between beta-blockers and intrauterine fetal growth restriction. Patients should be counseled appropriately and the obstetrics team can monitor fetal growth during pregnancy.
Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Prevention, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Prevention, CHD and Pediatrics and Quality Improvement, Hypertension
Keywords: Adrenergic beta-Antagonists, Cleft Lip, Heart Defects, Congenital, Hypertension, Medicaid, Nervous System Malformations, Pre-Eclampsia, Pregnancy, Pregnancy Trimester, First, Primary Prevention, Risk
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