Association between hypertensive medication during pregnancy and risk of several maternal and neonatal outcomes in women with chronic hypertension: a population-based study

Background: Several studies have reported an association between perinatal complications and the severity of the hypertensive disease. The increasing number of pregnancies complicated by hypertension and the small assurance about the perinatal effects of hypertensive drug use during pregnancy involves the need of studying the better management of hypertensive mothers. Objective: To evaluate the association between maternal use of antihypertensive drugs and maternal and neonatal outcomes in women with chronic hypertension. Study design: We conducted a population-based study including all deliveries of hypertensive women that occurred between 2007–2017 in the Lombardy region, Italy. We evaluated the risk of several maternal and neonatal outcomes among women who filled antihypertensive prescriptions within the 20th week of gestation. Propensity score stratification was used to account for key potential confounders. Results: Out of 5,553 pregnancies, 2,138 were exposed to antihypertensive treatment. With respect to no-users, users of antihypertensive drugs showed an increased risk of preeclampsia (RR:1.68, 95%CI:1.42–1.99), low birth weight (1.30,1.14–1.48), and preterm birth (1.25,1.11–1.42). These results were consistent in a range of sensitivity and subgroup analyses. Conclusion: Early exposure to antihypertensive drugs in the first 20 weeks of gestation was associated with an increased risk of preeclampsia, low birth weight, and preterm birth.