Is Exercise during Pregnancy a Risk for Gestational Age and Preterm Delivery? Systematic Review and Meta-Analysis.

Traditionally, one of the primary concerns regarding exercise during pregnancy has been the potential of reducing gestational age and increasing the likelihood of preterm delivery. The aim of this study was to perform a systematic review about the effects of physical activity (PA) during pregnancy on gestational age and preterm delivery. A systematic review and two meta-analyses were performed (Registration No. CRD42022370770). Data sources from online databases were searched up to November 2022. The review exclusively included studies involving pregnant populations and interventions consisting of PA implemented during pregnancy. The primary outcomes analysed were gestational age, measured in weeks, and the occurrence of preterm deliveries. A total of 57 studies were analysed through two independent meta-analyses for the first one, no association was found between moderate exercise during pregnancy and gestational age (Z = 0.45, p = 0.65, ES = 0.08, 95% CI = -0.06-0.04, I2 = 42%, P heterogeneity = 0.001), showing the exercise group had a higher gestational age. In addition, no differences were found between groups in terms of number of preterm deliveries (RR = 0.96, (95% CI = 0.77-1.21, Z = 0.33, p = 0.74; ES = 0.07; I2 = 31%, P heterogeneity = 0.05)). The findings of this study indicate that there is no association between exercise during pregnancy and reduced gestational age or increased risk of preterm delivery in healthy pregnancies.