Blood pressure-lowering treatment for pregnant women with non-severe hypertension: a systematic review and meta-analysis.

Hypertensive disorders of pregnancy (HDP) significantly affect maternal and fetal health worldwide. This meta-analysis evaluated the effects of blood pressure (BP)-lowering treatment and identified the optimal BP target for improving outcomes. A systematic review and meta-analysis of randomized controlled trials were performed using data from MEDLINE, Cochrane Library, and Ichushi databases. Outcomes included severe hypertension (systolic BP ≥160 mmHg and/or diastolic BP ≥110 mmHg), eclampsia, preeclampsia (PE), PE with severe features, HELLP syndrome, placental abruption, cesarean section, neonatal death, stillbirth, neonatal intensive care unit admission, low birth weight (<2500 g), preterm birth (<34 and <37 weeks), and small-for-gestational-age infants (<10th percentile). Data were pooled using a random-effects model, and meta-regression was conducted to explore interactions by HDP subtypes and achieved BP levels. BP-lowering treatment significantly reduced the risks of severe hypertension (risk ratio [RR] 0.477, 95% confidence interval [CI], 0.391-0.582), PE (RR 0.819, 95% CI, 0.704-0.954), and preterm birth at <37 weeks (RR 0.856, 95% CI, 0.770-0.951), compared with placebo or no treatment. Moderate heterogeneity was observed for several outcomes, and publication bias was noted for severe hypertension and low birth weight. Subgroup analyses found no significant interaction between treatment effect and HDP subtypes (except for placental abruption) or achieved BP levels. Among pregnant women with non-severe hypertension (systolic BP 140-159 mmHg and/or diastolic BP 90-109 mmHg), targeting <140/90 mmHg significantly reduced the risks of severe hypertension, PE, and preterm birth at <37 weeks, suggesting this target as optimal for improving maternal and fetal outcomes.