The Effects of Exercise Conditioning in Normal and Overweight Pregnant Women on Blood Pressure and Heart Rate Variability

Abstract

Pre-pregnancy obesity is a risk factor for preeclampsia, gestational diabetes, and hypertension. Regular exercise during pregnancy has been shown to decrease the risk of these obstetrical complications. The purpose of this prospective study was to measure the effects of an exercise program in normal-weight and overweight/obese pregnant women on blood pressure (BP) and cardiac autonomic function, determined by heart rate variability (HRV) and baroreflex sensitivity (BRS). Twenty-two sedentary pregnant women, recruited at 20 weeks gestational age (GA), were grouped as normal weight or overweight/obese. They were systematically assigned to an exercise (walking) group or control (nonwalking) group after the first participants were randomly assigned. Women in the walking groups participated in a 16-week, low-intensity walking program. BP, HRV, and BRS were measured at rest and during exercise at the beginning (20 weeks GA) and end (36 weeks GA) of the walking program. Results indicated that women in the control groups (especially overweight women) showed changes in BP, HRV, and BRS over pregnancy that were not seen in the walking group. Overweight women in the control group increased resting systolic BP by 10 mmHg and diastolic BP by 7 mmHg. HRV declined in the control group but not in the walking group. A reduction in BRS and R-R interval at rest was found in all groups except the walking normal-weight group. The results suggest that an exercise program could attenuate the increase in BP and the loss of parasympathetic tone associated with pregnancy, especially in overweight women.

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

“…In summary, four articles provide results on maternal HRV, five on fetal HRV, and one on infant HRV. Of these, two articles were intervention studies [36, 43]. The intervention study performed by Stutzman et al [43] assessed the effects of low intensity exercise in normal weight (NW) and overweight and obese (OaO) pregnant women on maternal HRV.…”

“…Of these, two articles were intervention studies [36, 43]. The intervention study performed by Stutzman et al [43] assessed the effects of low intensity exercise in normal weight (NW) and overweight and obese (OaO) pregnant women on maternal HRV. The intervention study performed by Satyapriya et al [36] assessed the effect of yoga specifically designed for the second and third trimester of pregnancy, compared to standard prenatal exercise (intensity not specified) on maternal HRV.…”

“…of moderate to vigorous aerobic exercise/ 3 times a week; n  = 15) and control group ( n  = 15) a fetalF: RMSSD, VLF, LF, LF/HF, VLF/LF, VLF/HF, INTA continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometerGw36Mixed-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 pregnanciesMPAQ to retrospectively assess maternal physical activity behavior, specifically duration and intensity a fetalF: SDNN, RMSSD, VLF, LF, HF, VLF/LF, VLF/HF, LF/HFA continuous, 18 min simultaneous fetal-maternal MCG was recorded for each subject using an investigational 83-channel dedicated fetal biomagnetometerGw36Spearman correlations were used to assess relationships between maternal LTPA (intensity, duration) during third trimester and fetal heart measuresMultiple regression were additionally performed to assess how well LTPA intensity and duration predict fetal heart measuresStutzman [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/m 2 ), n  = 12 OaO b (BMI > 25.0 kg/m 2 )Measurements: laboratory testing at gw20 ± 2 and gw36Intervention:E: Instructed on a16 week progressive low-intensity walking exercise c , 5 days/week; n  = 6 OaO, n  = 5 NWC: 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/OaOmaternalM: LF, HF, TP, HF/TP, LP/HPBeat-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 monitorGw20 and gw36ANOVAs were used to obtain within and between group changes from gw20 to gw36May, [40]Prospective, longitudinal, non-blinded study to assess fetal heart measures depending on self-reported maternal exercise and fetal state N  = 61; 20–35 yearssingleton, low-risk pregnanciesMPAQ to retrospectively categorize women into exercise (≥ 30 min.…”

Effects of sleep disturbances during pregnancy on cardiac autonomic modulation in the resting state

“…This relationship may be explained by differences in daily physical activity between working and non-working participants. An increase of physical activities increased vagal modulation in pregnant women with obesity [24], and working women are likely more physically active than their non-working counterparts.…”

Exercise during pregnancy. A narrative review asking: what do we know?

“…The authors reported that this had no effect on BP but significantly increased the heart rate during the exercise session, with no negative long-term effect on either of these variables. In a prospective study involving 22 sedentary normal weight, overweight and obese pregnant women, Stutzman et al 63 investigated the effect of an exercise programme on BP and cardiac autonomic function as determined by heart rate variability (heart rate) and baroreflex sensitivity (BRS). The exercise programme consisted of walking (low-intensity exercise) for 16 weeks (from week 20 of pregnancy onwards).…”