Aerobic Exercise during Pregnancy and Presence of Fetal-Maternal Heart Rate Synchronization

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.

The influence of physical activity during pregnancy on maternal, fetal or infant heart rate variability: a systematic review

“…To assess self-reported maternal exercise, the authors used the ‘Modifiable Physical Activity Questionnaire’ (MPAQ). Finally, the remaining six articles [37–39, 41, 42, 47] were post-hoc analyses of subsets of the before mentioned longitudinal study of May et al [40]. Four of these post-hoc analyses referred to maternal or fetal HRV measurements performed in gestational week 36, one to maternal HRV measurements performed at 28, 32, and 36 weeks of gestation, and one to infant HRV measurements at one month of age.…”

“…)gw32:exercise: 1.8 ± 0.3control: 1.6 ± 0.3 (n.s. )gw36:exercise: 3.4 ± 0.3control: 3.1 ± 0.3 ( p  = 0.03)gw36:exercise: 2.0 ± 0.5control: 1.7 ± 0.3 ( p  = 0.03)Satyapriya [36]Changes in maternal HRV pre and during exercise session and pre and post exercise session (acute effects) at gw20 and gw36 (effects over time)Important: differences between maternal HRV measurements at gw20 and gw36 (effects over time) were not reported to be tested for significance---------( F fetal, gw gestational week, HRV heart rate variability, LTPA leisure-time physical activity, M maternal, ms millisecond, NW normal weight; n.s not significant, OaO overweight and obese, RMSSD root mean square of successive difference, SE standard error, sig significant, SDNN standard deviation of normal-to-normal intervals, TP total power)* p -values were not provided a data were log transformed to fulfill Gaussian distribution b kcal · min −1 c minutes during third trimester d level of significance was defined as p  ≤ 0.05 for all analyzes performed by Van Leeuwen et al [41] e measurements are only presented for active fetal state. Note that sample size is reduced at all time points (GA weeks 28 ( n  = 39), 32 ( n  = 37), 36 ( N  = 29)); results for quiet fetal state are not presented in this table because sample size is very small in this group…”

“…)gw36:exercise: 805.6 ± 1165.5control: 322.4 ± 387.4 (n.s. )Van Leeuwen, [41]Difference in maternal and fetal HRV between exercise and control group------------May, Suminski, [37]Correlation between continuous and non-continuous maternal LTPA and fetal HRVfetalcontinuous LTPA R  = 0.45 ( p  < 0.005)fetalcontinuous LTPA R  = 0.34 ( p  < 0.05)fetalcontinuous LTPA R  = 0.4 ( p  < 0.05)---non-continuous LTPA R  = 0.06 (n.s. )non-continuous LTPA R  = 0.29 (n.s.…”

“…)gw36:exercisepre session: 76.3 ± 4.9post session: 72.5 ± 6.0 ( p  = 0.001)controlpre session: 74.2 ± 9.5post session: 70.9 ± 7.4 (n.s. )gw36:exercisepre session: 23.2 ± 4.9post session: 27.5 ± 6.0 ( p  = 0.001)controlpre session: 25.0 ± 7.2post session: 29.1 ± 7.4 ( p  = 0.006)( F fetal, gw gestational week, HF high frequency, HRV heart rate variability, IntF intermediate frequency, LF low frequency, LTPA leisure-time physical activity, M maternal, ms millisecond, NW normal weight, n.s not significant, OaO overweight and obese, SE standard error, sig significant, VLF very low frequency) * p -values were not provided a data were log transformed to fulfil Gaussian distribution b kcal · min −1 c minutes during third trimester d level of significance was defined as p  ≤ 0.05 for all analyzes performed by Van Leeuwen et al [41] e measurements are only presented for active fetal state. Note that sample size is reduced at all time points (GA weeks 28 ( n  = 39), 32 ( n  = 37), 36 ( N  = 29)); results for quiet fetal state are not presented in this table because sample size is very small in this group…”

“…)gw36:exercise: 1.07 ± 1.5control: 1.2 ± 1.1 (n.s. )Van Leeuwen, [41]Difference in maternal and fetal HRV between exercise and control group------------May, Suminski, [37]Correlation between continuous and non-continuous maternal LTPA and fetal HRV------------May, Scholtz, [39]Difference in infant HRV between exercise and control groupinfantexercise: 5.02 ± 2.16control: 5.23 ± 2.24 (n.s. )---------Gustafson, [42]Difference in fetal HRV between exercise and control group adjusted for fetal breathingfetal a estimate: 0.20; SE: 0.37 (n.s.…”