Development and feasibility of a theory-guided and evidence-based physical activity intervention in pregnant women with high risk for gestational diabetes mellitus: a pilot clinical trial

BACKGROUND: Physical activity has been utilized as an effective strategy to prevent gestational diabetes mellitus (GDM). However, most pregnant women with high risk for GDM did not achieve the recommended physical activity level. Furthermore, relevant physical activity protocols have varied without theory-guided and evidence-based tailored to pregnant women with high risk for GDM. This study aimed to develop and pilot test a theory-guided and evidence-based physical activity intervention protocol for pregnant women with high risk for GDM. METHODS: The study design was guided by the Medical Research Council Framework for Developing and Evaluating Complex Intervention (the MRC framework). The preliminary protocol for physical activity intervention was developed based on self-efficacy theory, research evidence identified from systematic reviews and clinic trials, stakeholder engagement, context, and economic considerations. The preliminary intervention protocol was validated through a content validity study by an expert panel of 10 experts. A single-blinded randomized controlled trial (RCT) was designed to test the feasibility and acceptability of the intervention. RESULTS: The validity of the preliminary intervention protocol was excellent as consensus was achieved. The final 13 sessions of self-efficacy enhancing physical activity intervention protocol were developed, including knowledge education, exercise clinic visits and video, and group discussions with face-to-face and online blended sessions. In the feasibility study, 34 pregnant women with high risk for GDM were randomized for the intervention (n = 17) or the control group (n = 17). The recruitment and retention rates were 82.9% and 58.9%, respectively. Women in the intervention group had a lower incidence of GDM (26.7% vs. 36.5%) than the control group (P >0.05). All participants were satisfied with the intervention and agreed that the intervention was helpful. CONCLUSIONS: The developed self-efficacy-enhancing physical activity intervention is a feasible and acceptable intervention for enhancing physical activity among pregnant women with high risk for GDM and is ready to be tested in a more extensive RCT study. TRIAL REGISTRATION: The study was registered on 4 February 2022 (ChiCTR2200056355) by the Chinese Clini Trial Registry (CHiCTR). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12884-023-05995-7.