Influence of Light Intensity exercise During Pregnancy on Fetal Echocardiographic and Maternal Cardiovascular Measures

Abstract

Background: Although moderate intensity maternal exercise is recommended during pregnancy, most women do not achieve this level. Objective: This study aimed to determine the effects of supervised maternal light-intensity exercise on fetal cardiovascular measures in the 3rd trimester. Materials and Methods: We compared women participating in light-intensity (LI) stretching/breathing or no exercise (CON) across 24+ weeks of pregnancy Women with singleton pregnancies (<16 weeks), between 18-40 years, 18.5-34.99 kg/m2 BMI, and having no chronic health conditions were eligible. LI did 150 minutes light-intensity weekly exercise; CON did normal daily activities, but no exercise. Maternal measures included resting heart rate (HR) and blood pressure (BP). Fetal measures included estimated fetal weight (EFW), ponderal index (PI), HR, along with right and left ventricular measures (e.g., stroke volume, cardiac output, ejection fraction) at 36 weeks’ gestation. T-tests compared differences between groups; partial spearman rank correlations and regressions were performed to find relationships and predict fetal echocardiographic outcomes, controlling for fetal activity state. Results: Of 50 pregnant women (n=26 in LI, n=24 in CON), we found maternal exercise intensity influences fetal left ventricular heart flow, while maternal exercise duration influences fetal right ventricular outcomes. There were no differences (p>0.05) in fetal cardiac anatomical measures. Lastly, light intensity exercise and duration of exercise lower maternal blood pressure in late pregnancy. Conclusions:Light-intensity exercise is associated with improved fetal cardiac measures. Women benefit from light intensity exercise during pregnancy. Cardiovascular benefits from exercise for mother and child are dose dependent.