Low-Dose Aspirin for Prevention of Morbidity and Mortality From Preeclampsia: A Systematic Evidence Review for the U.S. Preventive Services Task Force

Study Questions:

Does low-dose aspirin reduce the risk of morbidity and mortality from preeclampsia?

Methods:

This was a systematic review and meta-analysis. Publications printed between January 2006 and June 2013, were identified using MEDLINE, Database of Abstracts of Reviews of Effects, PubMed, and Cochrane Central Register of Controlled Trials. Previous systematic reviews, clinical trial registries, and surveillance searches for large studies were also conducted. Randomized, controlled trials (RCTs) that assessed the outcomes among women at high preeclampsia risk and RCTs or large cohort studies of harms among women at any risk level were included. Two large, multisite RCTs and 13 smaller RCTs of high-risk women (eight good-quality RCTs) were included, in addition to six RCTs and two observational studies of average-risk women to assess harms (seven good-quality).

Results:

Depending on baseline risk, aspirin use was associated with absolute risk reductions of 2-5% for preeclampsia (relative risk [RR], 0.76; 95% confidence interval [CI], 0.62-0.95), 1-5% for intrauterine growth restriction (RR, 0.80; 95% CI, 0.65-0.99), and 2-4% for preterm birth (RR, 0.86; 95% CI, 0.76-0.98). No significant perinatal or maternal harms related to aspirin were identified, but rare harms could not be ruled out. Evidence on long-term outcomes was sparse, but 18-month follow-up from the largest trial found no developmental harms. Benefits may have been overestimated due to small study effects. Predictive intervals were not statistically significant. Future studies could shift findings toward the null.

Conclusions:

The investigators concluded that daily low-dose aspirin beginning as early as the second trimester prevented clinically important health outcomes. No harms were identified, but long-term evidence was limited.

Perspective:

These analyses suggest benefit associated with low-dose aspirin; in particular, lowering the risk related to preeclampsia. Among women at increased risk, such therapy may be beneficial; however, as the authors point out, larger trials and trials which include African American women are warranted.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, CHD & Pediatrics and Prevention, CHD & Pediatrics and Quality Improvement

Keywords: Risk, Infant, Newborn, Follow-Up Studies, Platelet Aggregation Inhibitors, Premature Birth, Numbers Needed To Treat, Pre-Eclampsia, Registries, Research Personnel, Confidence Intervals


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