Characterization of antihypertensive medication use during pregnancy in a cohort from two academic medical centers

Introduction: Hypertensive disorders of pregnancy (HDP) are rising in prevalence and associated with adverse maternal and infant health outcomes. Current guidelines recommend labetalol, nifedipine, and methyldopa as acceptable first-line agents to treat HDP. However, the best practices regarding antihypertensive medication usage and selection remain unclear due to a lack of clinical trial evidence comparing the safety and effectiveness of different treatment strategies. Methods: A retrospective, observational cohort study was conducted in 1641 women with a physician diagnosis of HDP who delivered at Duke University or the University of North Carolina at Chapel Hill from 2014-2017. Use of any antihypertensive medication, and the agent selected, at any encounter during pregnancy and/or on the delivery date was collected from the electronic health record. Antihypertensive medication use and frequencies were compared across HDP diagnosis (eclampsia/severe preeclampsia, chronic hypertension with superimposed preeclampsia, preeclampsia, gestational hypertension) by Chi-square tests and multivariable logistic regression. Results: The mean (±SD) age of the population was 30.5 ± 6.5 years, 41.0% and 15.7% self-identified as Black and Hispanic, respectively, and 30.5% had a pre-pregnancy hypertension history. Antihypertensive medications were used during pregnancy or on the date of delivery in 1276 (77.8%) patients overall. Labetalol (74.9%) was the most frequently used medication followed by nifedipine (29.6%) and hydralazine (20.5%). HDP type was the strongest independent factor associated with the decision to use an antihypertensive agent. Relative to gestational hypertension, antihypertensive use was significantly more likely (odds ratio [95% CI]) in patients with severe preeclampsia (5.94 [3.85-9.16], P<0.001), chronic hypertension with superimposed preeclampsia (4.99 [3.46-7.19], P<0.001), and preeclampsia (2.13 [1.61-2.82], P