Early Administration of Low-Dose Aspirin for the Prevention of Severe and Mild Preeclampsia: A Systematic Review and Meta-Analysis

American Journal of Perinatology, 04/12/2012

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


  • 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.


  • 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.

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