Interventions in women with type 2 diabetes mellitus in the pre-pregnancy, pregnancy and postpartum periods to optimise care and health outcomes: A systematic review

Aims: Type 2 diabetes is a chronic condition affecting increasing numbers of women of reproductive age. Recent UK data show more severe adverse offspring outcomes (stillbirth, neonatal death) than in infants of those with Type 1 diabetes. This systematic review aimed to evaluate randomised controlled trials (RCTs) undertaken in the pre-pregnancy, pregnancy and the postpartum periods in women with Type 2 diabetes, to optimise care and health outcomes. Methods: Six electronic databases were searched for eligible studies from January 2000 to September 2023; eligibility included RCTs of behavioural components, supplementation, pharmacotherapy and/or medical devices. Studies were screened in duplicate, and data were extracted on outcomes including behavioural, anthropometry, clinical measures and maternal and offspring outcomes. A narrative synthesis was performed. Results: Eleven trials (12 papers) were included (total 1356 women with Type 2 diabetes, n = 25–502). Ten interventions were conducted in pregnancy, and one in the postpartum period. No pre-pregnancy RCTs were identified. Interventions included pharmacotherapies and supplementation, a diabetes-specific antenatal programme, continuous glucose monitoring and postpartum exercise. We found a paucity of interventions limited by inadequate design, statistical power and poor reporting. The largest Type 2 diabetes pregnancy study to date demonstrated evidence of benefit for adding metformin to a standard insulin regimen compared to insulin alone. Other interventions need replication in larger studies among more diverse groups. Conclusion: This review identified few RCTs targeting women of reproductive age with Type 2 diabetes particularly lacking in the preconception and postpartum periods. Tailored pre-pregnancy, pregnancy and postpartum interventions for women with Type 2 diabetes to optimise care and health outcomes are urgently needed.