Abstract
INTRODUCTION: Sleep disturbances are common in pregnancy and linked to adverse maternal and fetal outcomes. Physical activity is a promising non-pharmacological strategy to improve sleep; however, few studies have objectively examined this relationship during early pregnancy. This pilot study examined whether participation in an eight-week, online, participant-centered physical activity program (Healthy Mamas Program) was associated with changes in objectively measured sleep among pregnant Australian women in their first trimester. METHODS: A prospective intervention study was conducted between March 2021 and November 2022. Eleven women who were not regularly active at baseline (<75 minutes/week) wore Fitbit Charge 2 devices to track daily physical activity and sleep. Participants completed a seven-day baseline assessment, followed by the eight-week intervention and a seven-day post-program assessment. Sleep and physical activity variables were transformed as appropriate. Descriptive statistics, Pearson correlations, and linear mixed-effects models were used to assess associations and changes over time. RESULTS: Participants engaged in 244.50 minutes of total physical activity per day, primarily of light intensity. No significant change in physical activity was observed over time (p=0.17). Participants averaged 5.9 hours of sleep per night, with 23.18 nightly awakenings and a mean sleep efficiency of 78.91%. There were no significant associations between physical activity and sleep duration (p=0.130) or efficiency. CONCLUSIONS: Findings suggest that, while feasible, the intervention did not significantly improve physical activity or sleep. Both behaviors remained below recommended levels. These results highlight the need for trimester-sensitive, accessible interventions to promote physical activity and improve sleep quality during pregnancy.