 This study evaluates the effectiveness of various interventions for preventing gestational diabetes mellitus, GDM, based on individual characteristics such as body mass index, polycystic ovary syndrome, history of GDM, and parity. The results suggest that physical activity is more effective in reducing the risk of GDM in women with a normal bear mire baseline, while combined diet and physical activity interventions are more effective in women without PCOs or a history of GDM. Metformin interventions are more effective in women with PCOs or when commenced preconception. Future research should include trials commencing preconception and provide results disaggregated by a priori defined participant characteristics to predict GDM prevention through interventions. This article was authored by Sulim, Wubit Warkutakhele, Pimbali Kvesko, and others.