Prevention of preeclampsia with aspirin: a systematic review of guidelines and evaluation of recommendation evidence

Objectives Preeclampsia is a major cause of maternal and infant mortality and morbidity. Randomized evidence has shown aspirin significantly reduces preterm preeclampsia and perinatal death. Our objectives were to systematically review clinical practice guidelines and other statements to evaluate recommendations on aspirin for preeclampsia prevention. Methods Ten databases were searched for clinical practice guidelines and other statements (e.g., position statements, consensus statements). All steps were done by two reviewers. Guideline quality was assessed using a modified Appraisal of Guidelines for Research and Evaluation-II Instrument and the AGREE-Recommendation Excellence tool. Descriptive statistics were calculated. Results Thirty-two out of 34 statements on the prevention of preeclampsia had recommendations on aspirin use, particularly in high risk women. Approximately 75% of statements with recommendations on aspirin use were supported by systematic review or randomized controlled trial evidence. Only three statements reported aspirin's significant reduction in preterm preeclampsia, and none described the significant reduction in perinatal death. A minority of statements were rated as high-quality in all domains (47% in all domains of the Appraisal of Guidelines for Research and Evaluation-II tool, 19% in all domains of the AGREE-Recommendation Excellence tool and 13% in all domains of both tools). Conclusions Worldwide, only 75% of statements on aspirin use for the prevention of preeclampsia were supported by high quality evidence but only 9% mentioned evidence clinicians would likely find most compelling such as reductions in preterm preeclampsia. The AGREE tools indicated many documents could benefit from methodological improvement.