Table 2 Cohort and study characteristics
First author, year | Study design | Sample (pregnant women) | Intervention, exercise mode, PA determination | HRV outcomes (maternal/fetal/infant) | HRV measure technique | Time(s) of measurement | Data analysis |
|---|---|---|---|---|---|---|---|
May, [47] | Post-hoc analysis of maternal magnetocardiograms (May et al. [40]) to assess maternal heart measures depending on maternal exercise behavior (exercise vs. control group) at different weeks of gestation | N = 56 (gw36 N = 51); 20–39 years singleton, low-risk pregnancies | MPAQ to retrospectively categorize women into exercise (≥30 min. aerobic exercise/ 3 times a week) and control groupa | maternal M: SDNN, RMSSD, VLF, LF, HF, LF/HF | 3 continuous, 18 min simultaneous fetal-maternal MCG were recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | Gw28, gw32, and gw36 | Students t-test and Wilcoxon rank sum test to contrast variables between exercise and control groups |
Van Leeuwen, [41] | Post-hoc analysis of fetal-maternal magnetocardiograms (May et al. [40]) to assess maternal and fetal heart measures depending on maternal exercise behavior (exercise vs. control group) | N = 40; 20–35 years singleton, low-risk pregnancies | MPAQ to retrospectively categorize women into exercise (≥ 30 min. of moderate to vigorous aerobic exercise/ 3 times a week; n = 21) and control group (n = 19)a | maternal, fetal M: SDNN, RMSSD F: SDNN, RMSSD | A continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | Gw36 | Comparison between control and exercise groups using Mann-Whitney-U test |
May, Suminski, [37] | Post-hoc analysis of fetal magnetocardiograms (May et al. [40]) to assess fetal heart measures depending on the duration of maternal continuous and non-continuous leisure-time physical activity | N = 40; 23–39 years singleton, low-risk pregnancies | MPAQ to retrospectively classify whether the women perform continuous (e.g., walking, jogging) or non-continuous (e.g. weight lifting, yoga)a leisure-time physical activity | fetal F: SDNN, RMSSD, VLF, LF, HF | A continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | Gw36 | Pearson Product Monument correlation to assess relationships between duration (min) of maternal continuous and non-continuous LTPA and fetal heart measures; Multiple regression analyses to predict fetal heart measures |
May, Scholtz, [39] | Post-hoc analysis of a subset of infants from a prospective longitudinal pregnancy study (May et al. [40]) to assess infant heart measures depending on maternal exercise behavior (exercise vs. control) | N = 43; 20–35 years, singleton, low-risk pregnancies | MPAQ to retrospectively categorize infants of women who were in the exercise (≥ 30 min. of moderate to vigorous aerobic exercise/ 3 times a week; n = 16) and control group (n = 27)a | infant I: SDNN, RMSSD, LF, HF | A continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | One month of age | Student´s t-tests to compare infant HRV measures between exercise and control group |
Gustafson, [42] | Post-hoc analysis of fetal magnetocardiograms (May et al. [40]) to assess fetal heart measures depending on maternal exercise (exercise vs. control) | N = 30; 20–35 years, singleton, low-risk pregnancies | MPAQ to retrospectively categorize women into exercise (≥ 30 min. of moderate to vigorous aerobic exercise/ 3 times a week; n = 15) and control group (n = 15)a | fetal F: RMSSD, VLF, LF, LF/HF, VLF/LF, VLF/HF, INT | A continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | Gw36 | Mixed-effects models with post-hoc comparisons. Comparisons for exercise vs. control were adjusted for breathing patterns (breathing vs. apnea) |
May, [38] | Post-hoc analysis of fetal magnetocardiograms (May et al. [40]) to assess effects of maternal exercise dose on fetal heart measures | N = 50; 23–39 years, singleton, low-risk pregnancies | MPAQ to retrospectively assess maternal physical activity behavior, specifically duration and intensitya | fetal F: SDNN, RMSSD, VLF, LF, HF, VLF/LF, VLF/HF, LF/HF | A continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | Gw36 | Spearman correlations were used to assess relationships between maternal LTPA (intensity, duration) during third trimester and fetal heart measures Multiple regression were additionally performed to assess how well LTPA intensity and duration predict fetal heart measures |
Stutzman [43] | Prospective controlled interventional study to assess pre-to-post changes of exercise conditioning on HRV in normal and overweight women. HRV was measured in supine position and during low-intensity exercise | N = 22; healthy, singleton pregnancy; n = 10 NW (BMI < 25.0 kg/m2), n = 12 OaOb(BMI > 25.0 kg/m2) | Measurements: laboratory testing at gw20 ± 2 and gw36 Intervention: E: Instructed on a16 week progressive low-intensity walking exercisec, 5 days/week; n = 6 OaO, n = 5 NW C: Activity log only; n = 6 OaO, n = 5 NW →4 group design: a) walking/NW, b) non-walking/NW, c) walking/OaO, d) non-walking/OaO | maternal M: LF, HF, TP, HF/TP, LP/HP | Beat-by-beat R-R intervals were obtained and recorded continuously during testing using three latex-free standard surface ECG electrodes and a Spacelab 514 cardiac monitor | Gw20 and gw36 | ANOVAs were used to obtain within and between group changes from gw20 to gw36 |
May, [40] | Prospective, longitudinal, non-blinded study to assess fetal heart measures depending on self-reported maternal exercise and fetal state | N = 61; 20–35 years singleton, low-risk pregnancies | MPAQ to retrospectively categorize women into exercise (≥ 30 min. of moderate to vigorous aerobic exercise/ 3 times a week; n = 26) and control group (n = 35)a | fetal F: SDNN, RMSSD, VLF, LF, IntF, HF | 3 continuous, 18 min simultaneous fetal-maternal MCG were recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometer | Gw28, gw32, and gw36 | Post-hoc comparisons to obtain changes in fetal heart outcomes between exercise and control groups depending on fetal state (active vs. passive) at gw28, gw32, and gw36 |
Satyapriya [36] | Prospective, RCT to assess the influence of yoga on maternal HRV (two-group, pre-post-design). Measurements were changes in HRV pre and during exercise session as well as pre and post exercise session (acute effects) at gw20 and gw36 (effects over intervention time; not tested for significance) | N = 90; 20–35 years; mean BMI: 25.1 (E) and 25.6 (C) | Intervention: E: two modules of integrated yoga, specifically designed for the second and third trimester of pregnancy (n = 45) C: standard prenatal exercise (n = 45) | Maternal M: LF, HF, LF/HF | Electrocardiogram was recorded continuously for 5 min before, 10 min during and 5 min after intervention | Gw20 and gw36 Measuring pre, during, and post each session | ANOVAs to obtain within and between group differences in maternal HRV between exercise and control group |