Influence of Prenatal Aerobic Exercise on Fetal Morphometry

Objective The purpose of this study was to determine the effects of supervised prenatal aerobic exercise on fetal morphometrics at 36 weeks of gestation. Methods This study used data from a, 24-week, two-arm randomized controlled trial: aerobic exercise (EX) and stretching/breathing comparison group (CON). Singleton pregnancies (< 16 weeks pregnant) and women aged 18 to 40 years, BMI between 18.5 and 34.99 kg/m 2 , and no preexisting chronic health conditions were eligible. The EX group participated in 150 min of moderate-intensity weekly exercise while CON group participated in low-intensity stretching/breathing. Fetal morphometric outcomes included estimated fetal weight (EFW), ponderal index (PI), abdominal circumference (AC), anterior abdominal wall thickness (AAWT), fat mass, percent body fat, fat-free mass, assessed at 36 weeks gestation. Partial spearman rank correlations were performed, adjusting for 3 rd trimester weight gain. Results Of the 128 pregnant women randomized, 83 (EX [n = 46] and CON [n = 37]) were eligible for analyses. Intention-to-treat analysis showed no differences in EFW (rho s = − 0.13; p = 0.28), PI (rho s = 0.03; p = 0.81), AC (rho s = − 0.22; p = 0.09), AAWT (rho s = − 0.11; p = 0.40), fat mass (rho s = − 0.16; p = 0.23), percent body fat (rho s = − 0.10; p = 0.43), and fat-free mass (rho s = − 0.22; p = 0.08), after adjusting for 3rd trimester weight gain. Similar results were observed in the per protocol analyses. Conclusions For Practice Moderate-intensity aerobic exercise during pregnancy was not associated with select fetal morphometrics at 36 weeks gestation. Potential differences in offspring morphometrics may only appear in the postnatal period, as previously documented. Further research into offspring tissue composition after birth is encouraged, specifically studies investigating differences in cellular signaling pathways related to adipose and skeletal muscle tissue development.