Effects of Maternal Exercise Type on Infant Cardiac Autonomic Nervous System

Abstract

PURPOSE: The main purpose of this study is to measure the effects of aerobic, resistance, and combination training during pregnancy on offspring cardiac autonomic nervous system development at one-month postnatal age through heart rate and heart rate variability measures. METHODS: Participants were randomized into four groups, aerobic (n=6), and resistance (n=3), circuit (n=3) and a control (n=6) and trained from 16-weeks gestation until delivery. Exercise groups participated in three, 50-minute moderate-intensity exercise sessions per week. After birth, one-month infant HR and HRV measurements were obtained. Infant heart rate variability measures were not-normally distributed; therefore, we ran a Kruskal Wallis analysis to determine differences between groups. A 2x4 ANOVA was used to determine the differences between aerobic, resistance, combination, and control groups as well as within groups for each of the heart rate variability measures. Independent sample t-tests were used to determine any within group differences. RESULTS: Although there are no significant differences, there are potential trends based on autonomic measures For parasympathetic measures of RMSSD and HF, resistance group demonstrated higher values compared to controls. For sympathetic measure of VLF, all groups had increased HRV power relative to controls. For HRV measures indicative of parasympathetic AND sympathetic, all exercise groups demonstrated lower values of LF/HF and the resistance group had increased Total Power compared to controls. CONCLUSION: Overall, the observations of this study demonstrated that prenatal exercise training type exhibited no effect on one-month-old infant cardiac autonomic control. Importantly, these findings suggest that prenatal exercise training types poses no adverse nor beneficial effect on neonatal autonomic control, thus it is potentially safe for pregnant women to engage in various exercise training types in pregnancy.