Prevention of pre‐eclampsia with aspirin: A systematic review of guidelines and evaluation of the quality of recommendation evidence

BACKGROUND: Evidence has shown significant benefits of aspirin for preventing pre-eclampsia. OBJECTIVES: The objective of this study was to systematically review recommendations from clinical practice guidelines and other recommendation documents on aspirin for the prevention of pre-eclampsia. SEARCH STRATEGY: Ten databases were searched for statements from December 1, 2013, to January 1, 2022. SELECTION CRITERIA: Without language restrictions, the most recent version of documents was considered. DATA COLLECTION AND ANALYSIS: Two authors independently extracted recommendations. Guideline quality was assessed using a modified AGREE-II instrument and the AGREE-REX tool. MAIN RESULTS: Out of 48 statements on the prevention of pre-eclampsia, 46 had recommendations on use of aspirin. Of them, 39 were supported by evidence from systematic reviews or randomized controlled trials. Three statements reported aspirin's significant reductions in preterm pre-eclampsia and one in perinatal death. Concerning quality, 41% of statements were rated as high quality in all domains of the AGREE-II tool, 15% were rated high quality in all domains of the AGREE-REX tool, and 11% were rated high quality in all domains on both tools. CONCLUSIONS: While 96% of statements advocated for use of aspirin, only 9% reported a significant reduction in preterm pre-eclampsia or perinatal death. Based on the AGREE tools, future statements could use methodological improvement.