Gestational Diabetes Mellitus and Folic Acid Supplementation in Pregnant Women: A Systematic Review

Abstract

Background: Gestational diabetes mellitus (GDM) is a common pregnancy disorder screened for between the 24th and 28th weeks of gestation using oral glucose tolerance test. GDM has maternal and fetal health implications. Objective: To assess the relation between folic acid supplementation in pregnant women and the risk of developing GDM. Search Strategy: The search employed topic-based strategies designed for each database in June 2020. Databases searched were Pubmed, Cochrane Library, Embase and Lebanese American University online database. Selection Criteria: Studies eligible were those targeting the association of GDM development and folic acid supplementation, including pregnant women who have developed GDM and pregnant women who were on folic acid supplementation and developed GDM. Both interventional and observational studies were included. Data Collection and Analysis: Two reviewers extracted the data independently. A third reviewer checked the data for consistency and clarity. Data extracted included the sample characteristics, sample size and outcomes. Cohen’s κ was used to assess agreement between reviewers. All tools and processes were piloted prior to use. Risk of bias was assessed using the Newcastle-Ottawa Scale. Data was presented in a tabulated form. Main Results: Six studies showed a proportional relation between folic acid intake and GDM, two reported a protective effect, and one cohort found no association. Conclusion: The inconsistent results made the formulation of a definitive conclusion difficult. Hence, larger studies are needed.