A meta-analysis of low-dose aspirin for prevention of preeclampsia

Low-dose aspirin (LDA) is widely used for prevention of preeclampsia. However, conflicting results have been obtained from various studies.

The aim of our study was to evaluate the effect of LDA in prevention of preeclampsia in high-risk and low-risk women.

A total of 19 randomized control trials were identified using PUBMED search engine and Cochrane Clinical Trial register. The study population was divided into high-risk and low-risk groups. The effect measured was incidence of preeclampsia in women taking either LDA or placebo where the relative risk (RR) and the 95% confidence interval (CI) were calculated for both groups.

A total of 28237 women were studied, out of which 16550 were in the low-risk group while 11687 were in the high-risk group. The overall incidence of preeclampsia was 7.4%. With the aspirin group it was 6.9% while in the placebo group it was 7.8%. In the high-risk group there was 21% reduction in the risk of preeclampsia associated with the use of aspirin (RR 0.79, 95% CI 0.65-0.97). However, LDA is not effective in reducing the risk in low-risk population (RR 0.86, 95% CI 0.64-1.17).

LDA has a small effect in the prevention of preeclampsia in women considered to be at high risk for the disease. However, it is not effective in reducing the risk in the low-risk group.