Women who develop gestational diabetes mellitus (GDM) have a 60% lifetime risk of developing type 2 diabetes mellitus (T2D), which is already elevated within the first decade following childbirth. Despite the impact of lifestyle interventions to reduce long-term T2D risk in women with previous GDM, successful implementation of lifestyle interventions remains a barrier. Metformin is recommended for adults at increased risk of developing T2D; however, there is limited evidence of tolerability in the early postpartum period. Glucagon-like peptide 1 receptor agonists (GLP-1 RA) are effective at improving glycaemic status and body weight. However, GLP-1 RA have not been evaluated in the postpartum population. Finally, physical activity monitors may support behaviour changes related to physical activity to reduce long-term risk of T2D but are yet to be studied following GDM.

This will be a multicentre, randomised, open-label interventional pilot study. Using a 2x2 factorial design, we will examine the feasibility and acceptability of a pharmacotherapy intervention and a physical activity intervention in women with previous GDM at increased risk of developing T2D. Participants will be recruited from tertiary referral hospitals in Australia and will be randomised to receive either metformin alone or in combination with a GLP-1 RA and subsequently randomised to either a physical activity intervention involving activity monitor use, or usual care for 6 months, followed by a 6-month follow-up period. Primary feasibility outcomes include the acceptability and safety of the metformin and GLP-1 RA as measured through pill and injection counts, acceptability questionnaire and adverse events.

This trial is registered with the Australian and New Zealand Clinical Trials Registry (Registration Number: ACTRN12624001253594). This trial has received ethics approval from the South Eastern Sydney Local Health District Human Research Ethics Committee (Approval Number: 2024/ETH00042, protocol version v1.1, 28/02/2025).

Australian and New Zealand Clinical Trials Registry, Registration Number: ACTRN12624001253594.