Preventive effect of aspirin on preeclampsia in high‐risk pregnant women with stage 1 hypertension

Studies reported that women in a low‐risk cohort with stage 1 hypertension defined as 130–139 mmHg/80–89 mmHg, according to the American College of Cardiology/American Heart Association, are more likely to develop into preeclampsia than women with normotensive in the early gestation. In this study, the authors investigated whether preeclampsia was more likely to occur in stage 1 hypertensive women compared to the normotensive pregnant women in a high‐risk cohort, which was based on the randomized controlled trial of "Low‐dose Aspirin in the Prevention of Preeclampsia in China." Meanwhile, the authors further evaluated the preventive effect of aspirin for preeclampsia in stage 1 hypertension subset. In women enrolled at or before 16 weeks of gestation, in the control group, the preeclampsia occurrence was significantly higher in stage 1 hypertensive woman than in the normotensive women (20.4% vs. 6.2%, aOR 3.960, 95% CI 1.299–12.074, p = .016), while no difference was observed in the aspirin group (4.5% vs. 4.2%, aOR 0.921, 95% CI 0.140–6.070, p = .932). In stage 1 hypertension, the incidences of preeclampsia and preterm birth were significantly lower in the aspirin group as compared to the control group (4.5% vs. 20.4%, aOR 0.139, 95% CI 0.027–0.716, p = .018; 4.5% vs. 18.4%, aOR 0.141, 95% CI 0.025–0.782, p = .025). Compared with the control group, the aspirin group displayed significantly prolonged gestational age at delivery (38.6 ± 1.2 vs. 37.4 ± 3.4, p = .042). This study indicates that the newly classified stage 1 hypertension might be an additional risk factor for preeclampsia in Chinese high‐risk pregnant women, and aspirin intervention might be useful.