Pre-Pregnancy Diet and/or Physical Activity Interventions for the Prevention of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis.

Background: Gestational diabetes mellitus (GDM) is associated with short- and long-term adverse health outcomes for women and their infants. Antenatal diet and/or physical activity interventions have not been effective at preventing GDM, and currently, it is not clear whether intervening similarly prior to pregnancy is beneficial.

Aims: This review aims to evaluate the impact of pre-pregnancy diet and/or physical activity interventions on rates of GDM and other maternal and infant health outcomes.

Methods: A systematic literature search of the online databases Embase, Pubmed, Cochrane Central Register of Controlled Trials, Ovid MEDLINE and CINAHL was conducted from inception to 7 February 2023. All randomised controlled trials comparing pre-pregnancy diet and/or physical activity interventions with standard care or control were included. Data were extracted by two reviewers independently, and meta-analysis was performed using random-effects models to calculate summary effect estimates and 95% confidence intervals. The primary outcome was GDM. Five randomised trials assessing pre-pregnancy diet and/or physical activity interventions (n = 1924 women) were included.

Results: Pre-pregnancy diet and/or physical activity interventions were not associated with a significant difference in rates of GDM (2 studies; n = 214; RR 1.19, 95% CI 0.81, 1.75). There were no statistically significant differences for any of the secondary maternal or infant outcomes reported. There was significant heterogeneity between studies with regard to type, duration and intensity of the pre-pregnancy diet and/or physical activity interventions.

Conclusions: There was no evidence that pre-pregnancy diet and/or physical activity interventions reduced the risk for GDM or other adverse maternal and infant outcomes.