Regular Maternal Exercise Dose and Fetal Heart Outcome
ABSTRACT Our previous research found lower fetal HR and increased HR variability (HRV) in women who exercised during pregnancy. This finding is similar to the adult heart training response at rest due to aerobic exercise. Dose-response associations have been found between physical activity and cardiorespiratory fitness in adults. Therefore, our objective was to determine whether there is a dose-response relationship between maternal physical activity and fetal HR, HRV, and sympathovagal balance.
Pregnant women completed a physical activity questionnaire and magnetocardiogram (magnetic correlate to ECG) recordings at 36-wk gestational age. Women reported the duration, intensity, and frequency of each activity for each month of pregnancy as well as 3 months before pregnancy. These values were used to calculate maternal physical activity measures for each participant. Relationships between fetal HR, HRV, and sympathovagal balance at 36-wk gestational age and maternal physical activity (n = 50 pairs) during the third trimester were assessed by Spearman correlations. Regression analysis was performed to further examine these relationships after controlling for maternal and fetal covariates (maternal age, maternal resting HR, maternal weight gain, prepregnancy body mass index (BMI), and fetal activity state).
The regression analyses showed that maternal physical activity intensity (kcal·min(-1)) was negatively associated with HR in the active fetal state (P < 0.05), and physical activity duration (minutes during the third trimester) was positively associated with fetal HRV (P < 0.05). There were no statistically significant relationships with maternal physical activity on measures of fetal sympathovagal balance.
Maternal physical activity dose during the third trimester is associated with resting fetal heart effects similar to a trained response. Future studies on the health benefits of this fetal response are highly warranted.
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ABSTRACT: Maternal leisure-time physical activity (LTPA) improves cardiac autonomic function in the fetus. The specific physical activity attributes (e.g., mode) that produce this benefit are not well understood. To determine if more time spent performing non-continuous LTPA during pregnancy is significantly associated with lower fetal heart rate (HR) and increased heart rate variability (HRV). This paper presents a retrospective analysis of previously reported data. Fetal magnetocardiograms (MCG) were recorded from 40 pregnant women at 36-wk gestational age. Metrics of fetal HR and HRV, self-reported min of continuous and non-continuous LTPA performed during the 3-months preceding the 36-wk assessment point and covariates (maternal weight change pre to 36-wk, age, and resting HR and fetal activity state during MCG recordings. Positive correlations were significant (p<0.05) between min of continuous LTPA, the time domain metrics that describe fetal overall HRV, short-term HRV and a frequency domain metric that reflects vagal activity. Time spent in non-continuous LTPA was positively correlated (p<0.05) with two HRV metrics that reflect fetal overall HRV. In the multiple regression analyses, minutes of non-continuous LTPA remained associated with fetal vagal activity (p<0.05) and the relationships between minutes of non-continuous LTPA and fetal overall HRV (p<0.005) persisted. These data suggest non-continuous physical activity provides unique benefits to the fetal autonomic nervous system that may give the fetus an adaptive advantage. Further studies are needed to understand the physiological mechanisms and long-term health effects of physical activity (both non-continuous and continuous) performed during pregnancy to both women and their offspring.Early human development 04/2014; 90(7). DOI:10.1016/j.earlhumdev.2014.04.009 · 1.93 Impact Factor
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ABSTRACT: Transgenerational epigenetics, the study of non-genetic transfer of information from one generation to the next, has gained much attention in the past few decades due to the fact that, in many instances, epigenetic processes outweigh direct genetic processes in the manifestation of aberrant phenotypes across several generations. Maternal effects, or the influences of maternal environment, phenotype, and/or genotype on offsprings' phenotypes, independently of the offsprings' genotypes, are a subcategory of transgenerational epigenetics. Due to the intimate role of the mother during early development in animals, there is much interest in investigating the means by which maternal effects can shape the individual. Maternal effects are responsible for cellular organization, determination of the body axis, initiation and maturation of organ systems, and physiological performance of a wide variety of species and biological systems. The cardiovascular system is the first to become functional and can significantly influence the development of other organ systems. Thus, it is important to elucidate the role of maternal effects in cardiovascular development, and to understand its impact on adult cardiovascular health. Topics to be addressed include: (1) how and when do maternal effects change the developmental trajectory of the cardiovascular system to permanently alter the adult's cardiovascular phenotype, (2) what molecular mechanisms have been associated with maternally induced cardiovascular phenotypes, and (3) what are the evolutionary implications of maternally mediated changes in cardiovascular phenotype?Integrative and Comparative Biology 05/2014; DOI:10.1093/icb/icu031 · 2.97 Impact Factor
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ABSTRACT: Communication between maternal-fetal immune systems: development of immune tolerance.•Pathways by which immune dysfunction could contribute to neurodevelopmental disorders.•Effects of prenatal/perinatal stress and immune activity on CNS development/function.•Effects of prenatal/perinatal malnutrition on immune and CNS development/function.•Health benefits of physical activity during pregnancy for mother, fetus and infant.Brain Research 11/2014; DOI:10.1016/j.brainres.2014.10.051 · 2.83 Impact Factor