Bateman BT, et al. - In this cohort study, researchers estimated the risk of major congenital malformations related to exposure to β-blockers (class of antihypertensive medications that are commonly used in pregnancy) during the first trimester. According to results, in the first trimester, maternal use of β-blockers is not associated with a significant increase in the risk of overall malformations or cardiac malformations, irrespective of measured confounders.

Methods

• This study was conducted using health registries in the five Nordic countries and the US Medicaid database.
• Study participants included pregnant women with hypertension and their offspring.
• Exposure to β-blockers in the first-trimester was evaluated.
• Any major congenital malformation, cardiac malformations, cleft lip or palate, and central nervous system (CNS) malformations were the included outcomes.
• Researchers used propensity score stratification to control for potential confounders.

Results

• Of the 3,577 women with hypertensive pregnancies in the Nordic cohort and 14,900 in the US cohort, 682 (19.1%) and 1,668 (11.2%) were exposed to β-blockers in the first trimester, respectively.
• Findings revealed that the pooled adjusted relative risk (RR) and risk difference per 1,000 persons exposed (RD1000) related to β-blockers were 1.07 and 3.0, respectively, for any major malformation; 1.12 and 2.1 for any cardiac malformation; and 1.97 and 1.0 for cleft lip or palate.
• They noted that the adjusted RR was 1.37 and the RD1000 was 1.0 (based on US cohort data only) for CNS malformations.