Impact of an mhealth-supported behavioral lifestyle intervention on behavioral stage of change and physical activity in overweight and obese pregnancy: pears randomized controlled trial

INTRODUCTION: Regular physical activity (PA) during pregnancy could help reduce the risk of poor obstetric outcomes associated with maternal overweight and obesity. However, overweight and obese women report barriers to improving PA behaviors. Mobile health (mHealth) technologies offer potential to assist antenatal lifestyle interventions; however a paucity of evidence on mHealth effectiveness during pregnancy exists. Our aim was to investigate the impact of an mHealth‐supported lifestyle intervention on behavioral stage‐of‐change and PA among overweight and obese pregnant women. METHODS: This is an RCT of n=565 pregnant women (body mass index ≥25 kg/m2), randomized in early pregnancy to receive standard care (n=287) or a 'healthy lifestyle package' (n=278) involving nutrition and exercise advice supported by a smartphone app. In early (15 weeks) and late (28 weeks) pregnancy, behavioral stage‐of‐change score (1‐5; where a higher score is favored) was measured using a validated questionnaire to assess 'readiness' to change PA behaviors. PA was measured through questionnaires derived from the IPAQ. RESULTS: At baseline, there were no significant differences between intervention and control groups for demographics, stage‐of‐change score and PA. There was no difference in the proportion of women at stage 5 between intervention and control groups (32.4% vs. 33.3%; P=0.92). At 28 weeks, a higher proportion of the intervention group maintained or increased stage‐of‐change score for PA compared to controls (90.3% vs. 72.7%; P