Introduction: Whether maternal sedentary behaviour is associated with fetal overgrowth is unclear. In a systematic review (PROSPERO CRD42024551669), we aimed to evaluate the relationship of sedentary behaviour during pregnancy with fetal growth. Methods: Five databases were searched up to June 2024. We included studies of singleton pregnancies with data on self-reported and objective sedentary behaviour at any time point during pregnancy and offspring birthweight and/or adiposity, excluding studies limited to women with diabetes, on bedrest, or with major medical co-morbidities. Two independent reviewers screened studies, assessed quality and risk of bias and performed data extraction. For a subset of observational studies and randomized trials (RCTs), we performed meta-analyses using random-effects models. Results: A total of 36 studies (n=666,800; n=29 observational and n=7 RCTs) were included. Qualitative results showed no consistent association of maternal sedentary behaviour with fetal birthweight or adiposity. Results of meta-analysis showed no difference in birthweight for offspring delivered by sedentary versus active mothers, for both observational studies (n=12; SMD=0.24, 95% CI -0.52, 1.00; I2=92.4%) and RCTs (n=7; SMD=0.08, 95%CI -0.09, 0.25; I2=0.00%), overall and for subgroup analyses stratified by method of assessment of sedentary behaviour and sedentary behaviour definition. Sensitivity analysis of observational studies, excluding an outlier study that contributed significant heterogeneity, showed higher birthweight among offspring of sedentary versus active mothers (n=11; SMD=0.27, 95%CI 0.18, 0.36; I2=87.0%). Results from RCTs were considered exploratory as these did not directly measure sedentary behaviour. Quality assessment showed that most studies had risk of bias in at least one domain. Substantial heterogeneity across studies in sedentary behaviour definitions, measurement methods and timepoint of assessment contributed to very low to low certainty of evidence. Conclusion: Results indicate that maternal sedentary behaviour is not associated with offspring growth. While meta-analysis results of observational studies after excluding an outlier study suggest an association between greater maternal sedentary behaviour and increased offspring birthweight, elevated risk of bias and heterogeneity across studies suggest that current evidence is insufficient.
Satkunanathan et al. (Tue,) studied this question.