Does previous pregnancy experience improve folic acid supplementation uptake? A systematic review and meta-analysis

OBJECTIVE: To examine whether multiparous women have more or less folic acid uptake than primiparous women. OUTCOMES: Preconceptional, periconceptional and postconceptional folic acid use among all pregnant women and high risk pregnant women. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE-Ovid, CINAHL Ultimate, Scopus and ProQuest Medical. ELIGIBILITY CRITERIA: Observational epidemiological studies comparing folic acid use between primiparous and multiparous women, published in English from January 1994 to June 2024. DATA EXTRACTION AND SYNTHESIS: Two reviewers screened all papers meeting the eligibility criteria. One reviewer completed data extraction and assessed study quality using an adapted version of the Newcastle-Ottawa Scale. Three other reviewers independently assessed 10% of the studies as a quality check. Random-effects (DerSimonian and Laird) meta-analyses combined results for each outcome. Heterogeneity, risk of publication bias and certainty of evidence were assessed. RESULTS: =0.00%). The certainty of evidence was low for preconceptional, periconceptional and postconceptional uptake due to heterogeneity, and moderate for preconceptional uptake among high-risk women. CONCLUSIONS: Multiparous women were less likely to take folic acid preconceptional, periconceptional and postconceptionally, despite their previous pregnancy experience. Barriers to folic acid supplement uptake among multiparous women need to be identified, and strategies to address them in preconception, antenatal and interconception care should be investigated. PROSPERO REGISTRATION NUMBER: CRD42024553241.