A US open-label, multicenter, randomized trial concluded that in pregnant women with mild chronic high blood pressure (BP), a strategy of targeting BP<140/90 mm Hg was associated with better pregnancy outcomes than a strategy of reserving treatment only for severe high BP, with no increase in the risk of small-for-gestational-age birth weight. A total of 2408 women with mild chronic high BP and singleton fetuses at a gestational age <23 weeks were enrolled in the trial. The incidence of a primary outcome (a composite of preeclampsia with severe features, medically indicated preterm birth at < 35 weeks’ gestation, placental abruption, or fetal or neonatal death) was lower in the active-treatment group (targeting BP <140/90 mm Hg) than in the control group (to receive no treatment unless BP≥160/105 mm Hg; 30.2% vs. 37.0%), for an adjusted risk ratio of 0.82. The percentage of small-for-gestational-age birth weights below the 10th percentile was 11.2% in the active-treatment group and 10.4% in the control group (adjusted risk ratio, 1.04). The incidence of serious maternal complications was 2.1% and 2.8%; the incidence of severe neonatal complications was 2.0% and 2.6%; the incidence of any preeclampsia was 24.4% and 31.1%, and the incidence of preterm birth was 27.5% and 31.4% in the two groups, with risk ratio of 0.75, 0.77, 0.79, and 0.87, respectively. The findings are consistent with previous studies and support the treatment of pregnant women with chronic high BP with a BP target <140/90 mm Hg, including the continuation of their established therapy. Source: https://www.nejm.org/
