Physical activity during pregnancy plays a vital role in reducing the risk of preterm birth among women with gestational diabetes (GD), according to a comprehensive cohort study conducted in Hangzhou, China. The study, part of the Westlake Precision Birth Cohort, followed 1,427 pregnant women diagnosed with GD who wore wrist-worn accelerometers to track their activity levels.

      Key findings from the study reveal a strong association between moderate-to-vigorous physical activity (MVPA) and reduced preterm birth risk. Women engaging in 30 minutes or more of MVPA daily saw significant protective effects, with the greatest benefits observed at 74 minutes per day. Interestingly, the pattern of activity—whether regular or concentrated into a few days ("weekend warrior")—did not influence the protective effect.

      Highlights include:

      • Reduced Risk: A daily increase in MVPA reduced the odds of preterm birth by 36%, with an even stronger effect for those reaching 74 minutes of activity.

      • Flexible Patterns: Both consistent daily activity and concentrated patterns provided similar benefits, offering practical options for women with varying schedules.

      • Optimal Duration: The study demonstrated that 74 minutes of MVPA per day maximized benefits, with a clear L-shaped curve in risk reduction.

      The findings emphasize that even brief periods of concentrated activity can help mitigate preterm birth risks, supporting the inclusion of physical activity in guidelines for GD management. This is particularly relevant for women with time constraints or other barriers to daily exercise. Despite its strengths, the study acknowledges limitations such as the observational nature and reliance on accelerometers for a limited time. Further research is needed to confirm these findings across diverse populations and determine causal relationships.

      These results underscore the importance of promoting physical activity among pregnant women with GD, offering a feasible, low-risk strategy to improve maternal and fetal outcomes. The study lays the groundwork for developing tailored physical activity recommendations to support women in preventing adverse pregnancy outcomes.