Physical activity during pregnancy and the risks of excessive gestational weight gain and large-for-gestational-age: a dose-response meta-analysis of observational studies

BACKGROUND: Existing studies have established associations between physical activity and excessive gestational weight gain (EGWG) and large-for-gestational-age (LGA) infants. However, the dose-response relationships have been overlooked. METHODS: Studies on the associations between physical activity and EGWG/LGA were searched from eight databases, and 34 independent studies were finally included for eligibility. Quality assessment was performed using the Newcastle-Ottawa Scale (NOS), and publication bias was examined with Begg's and Egger's tests. Physical activity volume was harmonized to the common unit of MET-h/week. Restricted cubic splines were employed to model the dose-response relationship. All analyses were performed using Stata 16.0. RESULTS: Compared to the lowest level of physical activity, pregnant women with the highest level of physical activity had a 30% lower risk of EGWG and a 16% lower risk of delivering an LGA infant. A linear relationship was observed both throughout pregnancy and within specific trimesters. Overall, pregnant women who accumulated 10, 20, and 50 MET-h/week of physical activity had 4%, 9%, and 20% lower risks of EGWG, respectively. No significant dose-response association was observed during the second trimester. In contrast, during the third trimester, the corresponding reductions in EGWG risk were 8%, 16%, and 35%, respectively. CONCLUSION: Higher levels of physical activity were associated with a reduced risk of EGWG and LGA. A linear dose-response relationship between physical activity and EGWG was observed overall, particularly during the third trimester, highlighting the importance of maintaining adequate physical activity throughout pregnancy.