The Effectiveness of Lifestyle, Metformin, or Dietary Supplements for the Prevention of Gestational Diabetes Mellitus (GDM) by Participant Characteristics-A Systematic Review and Meta-analysis

The GDM prevalence has been rising, affecting 7-28% of pregnancies worldwide. Prior systematic reviews examining the success of interventions for GDM prevention have presented results where some interventions have modest effect and others, no effect. The impact of individual characteristics on the efficacy of interventions has not been thoroughly investigated. To address this knowledge gap, we performed a systematic review of controlled trials of lifestyle (diet and exercise), metformin and dietary supplement interventions initiated in the preconception, prenatal or postpartum period to assess whether participant characteristics impact the interventions’ effectiveness in GDM prevention. Overall, 116 studies met inclusion criteria (lifestyle n=92, metformin n=13 and dietary supplements n=12). Lifestyle, metformin and dietary supplements reduced GDM risk by 24% (RR 0.76, 95% CI 0.69-0.83), 34% (RR 0.66, 95% CI 0.47-0.93), and 45% (RR 0.55, 95% CI 0.36-0.83). With lifestyle, lower risks of GDM was seen in individuals with overweight or obesity (n=33, RR 0.70, 95% CI 0.59-0.83), without PCOS (n=3, RR 0.62, 95% CI 0.47-0.82) and without a history of GDM (n=13, RR 0.63, 95% CI 0.53-0.70) (p<0.05). With metformin, lower GDM risks were achieved when commenced prior to conception (n=3, RR 0.22, 95% CI 0.11-0.45)(p<0.01). Dietary supplements resulted in lower GDM risks among individuals with normal weight (n=1, RR 0.42, 95% CI 0.24-0.72), with prediabetes (n=1, RR 0.08, 95% CI 0.02-0.31), and when initiated before 20 weeks’ gestation (n=10, RR 0.46, 95% CI 0.30-0.71) (p<0.05). Given the potentially greater effectiveness of these interventions in certain groups of individuals, future research on tailored recommendations in precision GDM prevention, replacing the current ‘one-size-fits-all’ approach, is needed. Disclosure S.Lim: None. R.Taylor: None. M.Pathirana: None. K.Liu: None. G.G.Ukke: None. M.P.Bonham: None. M.Chen: None. A.J.Fawcett: None. S.C.Chivers: None. J.L.Josefson: None. W.W.Takele: None. L.M.Redman: Research Support; Dexcom, Inc., Abbott Nutrition, National Institute of Diabetes and Digestive and Kidney Diseases, Stock/Shareholder; ABGIL, Teladoc Health. K.Vesco: Research Support; Pfizer Inc. J.A.Grieger: None. N.Habibi: None. A.Quinteros: None. G.Leung: None. S.J.Zhou: None.