Impact of Antihypertensive Treatment on Maternal and Perinatal Outcomes in Pregnancy Complicated by Chronic Hypertension: A Systematic Review and Meta‐Analysis

BACKGROUND: Chronic hypertension complicates around 3% of all pregnancies. There is evidence that treating severe hypertension reduces maternal morbidity. This study aimed to systematically review randomized controlled trials of antihypertensive agents treating chronic hypertension in pregnancy to determine the effect of this intervention. METHODS AND RESULTS: Medline (via OVID), Embase (via OVID) and the Cochrane Trials Register were searched from their earliest entries until November 30, 2016. All randomized controlled trials evaluating antihypertensive treatments for chronic hypertension in pregnancy were included. Data were extracted and analyzed in Stata (version 14.1). Fifteen randomized controlled trials (1166 women) were identified for meta‐analysis. A clinically important reduction in the incidence of severe hypertension was seen with antihypertensive treatment versus no antihypertensive treatment/placebo (5 studies, 446 women; risk ratio 0.33, 95%CI 0.19‐0.56; I(2) 0.0%). There was no difference in the incidence of superimposed pre‐eclampsia (7 studies, 727 women; risk ratio 0.74, 95%CI 0.49‐1.11; I(2) 28.1%), stillbirth/neonatal death (4 studies, 667 women; risk ratio 0.37, 95%CI 0.11‐1.26; I(2) 0.0%), birth weight (7 studies, 802 women; weighted mean difference −60 g, 95%CI −200 to 80 g; I(2) 0.0%), or small for gestational age (4 studies, 369 women; risk ratio 1.01, 95%CI 0.53‐1.94; I(2) 0.0%) with antihypertensive treatment versus no treatment/placebo. CONCLUSIONS: Antihypertensive treatment reduces the risk of severe hypertension in pregnant women with chronic hypertension. A considerable paucity of data exists to guide choice of antihypertensive agent. Adequately powered head‐to‐head randomized controlled trials of commonly used antihypertensive agents are required to inform prescribing.