Step and weight tracking with targets and coaching interventions in gestational diabetes: A randomized factorial...

Pregnancy guidelines recommend moderate to vigorous physical activity of ≥150 min/week (7000 steps/day) and weight gain specific to prepregnancy weight category. We aimed to assess step and weight changes, with tracking to achieve individualized targets and with coaching conversations on physical activity and eating. The overarching goal was to identify interventions warranting integration and evaluation through a larger trial assessing perinatal outcomes.

In this feasibility trial, we randomized 227 participants (GDM clinics, 5 Canadian cities) to 'track & target,' 'coaching,' 'both,' or 'neither' arms. 'Track & target' participants monitored steps/day (counter) and weight (scale). We delivered weekly targets, applying algorithms that incorporated step and weight data and nudged towards recommendations. Coaching participants conversed weekly with a coach, who applied motivational communication methods. We examined changes in steps/day and weight, between trial entry and 37 weeks' gestation.

Weight change was guideline-concordant across arms. Steps/day averaged 6385 (SD 3406) at baselinue and were stable in the 'track & target' arm (change -59, 95 %CI -749 to 630). The other arms declined (coaching: -915, 95 %CI -1605 to -225; both -1183, 95 %CI -1979 to -386; neither -1456, 95 %CI -2193 to -718).

Our algorithm-driven step target strategy prevents step count decline, meriting study for perinatal impact.