We previously reported decreased fetal heart rate (HR) and increased heart rate variability (HRV) as a result of regular maternal aerobic exercise. These results suggest exposure to exercise throughout gestation influences prenatal cardiac autonomic control. It is unknown if these differences persist into the postnatal period.
Objective: We followed these infants into the postnatal period to determine if the changes we observed in the offspring of women who exercised during pregnancy would persist into the postnatal period.
Methods: Magnetocardiograms (MCG) were recorded at one month postnatal age from 18 exercise exposed (E) infants and 26 control (C) infants, not exposed to exercise. Cardiac metrics of rate and variability were obtained from the interbeat interval series.
Results: E Infants had significantly lower HR relative to C infants (p=0.03). Infants in the E group had significantly increased overall HRV: RMSSD (p=0.01) and SDNN (p=0.14). CVI and logRSA, parasympathetic measures, were also increased in E (p=0.02 and 0.01, respectively) infants. Power across low (0.08–0.2 Hz), high (0.4–1.7 Hz) frequency bands were significantly increased in the E group, respectively (p=0.001), (p=0.003). Sympathovagal balance (LF:HF) was equivocal between groups (p=0.96).
Conclusion: These findings demonstrate that lower fetal HR and increased HRV persist after birth in the offspring of women who exercised during pregnancy. This study has potential impact on cardiovascular health promotion and disease prevention.