A supervised prenatal group exercise program with high adherence reduces postpartum weight retention: a randomized clinical trial

Introduction Excessive weight gain during pregnancy has traditionally been associated with several health problems for the mother, fetus, and even the newborn. In fact, postpartum weight retention can be a consequence of this, posing a significant challenge for pregnant women and potentially associated with various health issues. Material and methods The purpose of this study was to examine whether a moderate intensity prenatal exercise program with high adherence affects postpartum weight retention up to one year after delivery. A randomized clinical trial (NCT04563065) was conducted, 350 pregnant women without obstetric contraindications were randomly assigned to an exercise group (EG; three 60-minute sessions per week from 8–15 to 38–40 weeks of gestation) or to a control group (CG). Maternal weight and secondary variables, including delivery characteristics and neonatal anthropometrics, were prospectively recorded using patient charts. Results The EG had reached an exercise adherence rate of 72.13%. The gestational weight gain did not differ between EG ( n = 150) and the CG ( n = 142) ( p > 0.05), and both groups gaining appropriately. At months one and two after delivery, the EG showed significantly lower weight retention than the CG (month one: 67.0 ± 10.87 kg vs. 71.08 ± 13.64; p = 0.009; 2 months: 66.03 ± 10.50 kg vs. 69.33 ± 13.78 kg; p = 0.04). Additionally, the EG had significantly lower postpartum weight retention after 10 ( p = 0.001) and 12 ( p = 0.005) months of delivery in comparison with the CG. Also, a significant group × time interaction was found for postpartum weight difference between study groups ( p < 0.001) with significant between-group differences at months 10 ( p = 0.002) and 12 ( p = 0.007). Delivery mode, episiotomy and perineal tear rates, gestational age at birth, neonatal weight, length, head circumference, and abdominal circumference did not show differences between groups differences ( p > 0.05). Conclusions Structured prenatal group exercise with high adherence reduces postpartum weight retention. Supervised prenatal group fitness may be a viable option to address barriers to physical activity such as social support or safety concerns, while also conferring health benefits such as postpartum recovery.