Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.

Peter Van Leeuwen,Dietrich Grönemeyer,Linda E May,Daniel Geue,Dirk Cysarz,Kathleen M Gustafson,Mathias Baumert

doi:10.1371/journal.pone.0106036

Abstract

It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization.MethodsIn 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance.ResultsIn the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data.ConclusionThe results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates.

Highlights

Normal prenatal development involves changes in fetal heart rate reflected in a gradual slowing of rates and accompanied by increases in heart rate variability (HRV)
Subject Population This was a retrospective analysis of fetal-maternal magnetocardiograms (MCGs) recorded from women who were enrolled in a study that was designed to measure the effect of maternal physical activity on the longitudinal development of fetal cardiac autonomic control
RR interval duration ranged from 373–518 ms and tended to be shorter in the fetuses whose mothers had not performed exercise

Summary

Introduction

Normal prenatal development involves changes in fetal heart rate reflected in a gradual slowing of rates and accompanied by increases in heart rate variability (HRV). As pregnancy progresses the increased occurrence of fetal waking and sleeping states, gross or fine motor activity, eye movements and breathing movements have all been associated with changes in fetal heart rate and HRV [1] [2] [3]. External stimuli such as music or speech lead to vibroacoustic stimulation which can affect fetal HRV [4] [5]. It has been shown that maternal hypoxia [6], hypothermia [7], stress [8], relaxation [9] or emotive state [10] can influence fetal HRV

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