Early administration of low-dose aspirin for the prevention of severe and mild preeclampsia: a systematic review and meta-analysis

Objective: To determine whether early administration of aspirin prevents severe and mild preeclampsia.

Study design: A systematic review and meta-analysis of randomized controlled trials were performed. Studies in which women were randomized at or before 16 weeks' gestation to low-dose aspirin versus placebo or no treatment were included. The outcomes of interest were severe preeclampsia and mild preeclampsia. Pooled relative risks with their 95% confidence intervals (CIs) were calculated.

Results: Among 7941 citations retrieved, 352 were completely reviewed and four studies (392 women) fulfilled the inclusion criteria and were analyzed. When compared with controls, aspirin started at ≤16 weeks was associated with a significant reduction in severe (relative risk: 0.22, 95% CI: 0.08 to 0.57) but not mild (relative risk: 0.81, 95% CI: 0.33 to 1.96) preeclampsia.

Conclusion: Low-dose aspirin initiated at or before 16 weeks reduces the risk of severe preeclampsia, but not mild preeclampsia.