Influence of maternal aerobic exercise during pregnancy on fetal cardiac function and outflow.

BACKGROUND: Risk factors for cardiovascular disease, the leading cause of death, have been documented in children as young as 3 years of age. Maternal environment (eg, exercise) influences fetal development and long-term health. Thus, the development of the fetal cardiovascular system during pregnancy is likely a preliminary indicator of cardiac health at birth and a proxy for the future risk of cardiovascular disease throughout life. OBJECTIVE: The purpose of this study was to assess the effects of supervised prenatal aerobic exercise at recommended levels on fetal cardiac function and outflow in the third trimester of pregnancy. We hypothesized that fetuses of aerobically trained women compared with fetuses of nonexercising women would exhibit increased cardiac function and greater cardiac output. STUDY DESIGN: Secondary data analyses of a 20-week, randomized controlled exercise intervention trial in pregnant women between 2015 and 2018 in Eastern North Carolina were performed. Eligibility criteria included pregnant women <16 weeks gestation, singleton pregnancy, aged 18-40 years, body mass index of 18.5-34.99 kg/m2, physician clearance letter for exercise participation, reliable transportation, and method of communication. Exclusion criteria included the presence of chronic conditions (eg, type 1 or 2 diabetes mellitus), current medications known to adversely affect fetal growth (eg, antidepressants), alcohol, smoking, or illicit drug use. The patient cohort consisted of 133 eligible pregnant women who were assigned randomly to either an aerobic exercise (n=66) group that participated in 150 minutes of supervised, moderate-intensity (40-59% VO2peak; 12-14 on Borg Rating of Perceived Exertion) aerobic exercise per week or a nonexercising group (n=61) that consisted of 150 minutes per week of light (<40% VO2peak) stretching and relaxation breathing techniques. Between 34 and 36 weeks gestation, a fetal echocardiogram was performed to assess fetal cardiac function, which included fetal heart rate, right- and left-ventricular stroke volume, stroke volume index, cardiac output, cardiac output index, and cardiac outflow that included pulmonary and aortic valve diameters, peak flow velocity, and peak flow velocity-time integral. Fetal activity state (quiet vs active) during the echocardiogram and maternal aerobic capacity served as covariates. Intention-to-treat and per-protocol (participants who attended ≥80% of exercise sessions) analysis of covariance regression models were performed. RESULTS: Of the 127 randomly assigned participants, 66 and 50 participants were included in the intention-to-treat and per-protocol analyses, respectively. Prenatal aerobic exercise significantly increased fetal right-ventricular cardiac measures of right ventricular stroke volume (P=.001) and stroke index via velocity-time integral (P=.003), right ventricular cardiac output (P=.002), cardiac index via velocity-time integral (P=.006), pulmonary artery diameter (P=.02), and pulmonary valve velocity-time integral (P=.03). Only in the intention-to-treat analysis was a significant difference in fetal left ventricular cardiac outflow observed; there was a greater aortic valve peak velocity (P=.04) found among fetuses of aerobically trained pregnant women. No other statistically significant between-group differences were found. CONCLUSION: The findings of this study demonstrate that participation in prenatal aerobic exercise at recommended levels may improve fetal cardiac function and outflow parameters. Follow-up cardiovascular measures in the postnatal period are needed to determine potential long-term effects on the offspring's cardiac function and outflow.

Influence of Prenatal Aerobic Exercise on Fetal Morphometry.

OBJECTIVE: The purpose of this study was to determine the effects of supervised prenatal aerobic exercise on fetal morphometrics at 36 weeks of gestation. METHODS: This study used data from a, 24-week, two-arm randomized controlled trial: aerobic exercise (EX) and stretching/breathing comparison group (CON). Singleton pregnancies (< 16 weeks pregnant) and women aged 18 to 40 years, BMI between 18.5 and 34.99 kg/m2, and no preexisting chronic health conditions were eligible. The EX group participated in 150 min of moderate-intensity weekly exercise while CON group participated in low-intensity stretching/breathing. Fetal morphometric outcomes included estimated fetal weight (EFW), ponderal index (PI), abdominal circumference (AC), anterior abdominal wall thickness (AAWT), fat mass, percent body fat, fat-free mass, assessed at 36 weeks gestation. Partial spearman rank correlations were performed, adjusting for 3rd trimester weight gain. RESULTS: Of the 128 pregnant women randomized, 83 (EX [n = 46] and CON [n = 37]) were eligible for analyses. Intention-to-treat analysis showed no differences in EFW (rhos = - 0.13; p = 0.28), PI (rhos = 0.03; p = 0.81), AC (rhos = - 0.22; p = 0.09), AAWT (rhos = - 0.11; p = 0.40), fat mass (rhos = - 0.16; p = 0.23), percent body fat (rhos = - 0.10; p = 0.43), and fat-free mass (rhos = - 0.22; p = 0.08), after adjusting for 3rd trimester weight gain. Similar results were observed in the per protocol analyses. CONCLUSIONS: For Practice Moderate-intensity aerobic exercise during pregnancy was not associated with select fetal morphometrics at 36 weeks gestation. Potential differences in offspring morphometrics may only appear in the postnatal period, as previously documented. Further research into offspring tissue composition after birth is encouraged, specifically studies investigating differences in cellular signaling pathways related to adipose and skeletal muscle tissue development.

Assessment of neonatal adrenal size using high resolution 2D ultrasound and its correlation with birth demographics and clinical outcomes.

OBJECTIVE: Assessment of adrenal function in a sick neonate remains a challenge in spite of major advances in neonatal care. We used 2D ultrasound of adrenal glands to assess maturity of adrenal glands in extremely preterm infants and sick term and near term infants. STUDY DESIGN: We collected demographics details of 99 mother-infants pairs (24-41 weeks) and obtained 2D ultrasound scans of adrenal glands in first week of life to measure adrenal volume, fetal zone size, and adrenal to kidney ratios. Relationship between adrenal measurements, antenatal factors, and postnatal outcomes were studied. RESULTS: We reported normative adrenal gland volume data during gestation from 80 appropriate for gestational age (AGA) infants. In a binary analysis, adrenal size was significantly related to gender, race, intrauterine growth restriction (IUGR), maternal chorioamnionitis, and maternal hypertension. Linear regression analysis showed that fetal zone is significantly related to not only gestational age but also chorioamnionitis and later development of intraventricular hemorrhage (IVH). Adrenal volume likewise is also related to gestational age, preeclampsia, and IVH. CONCLUSIONS: Antenatal maternal factors and uterine environment affects adrenal growth and development thus postnatal high resolution 2D US scan of adrenal glands can provide useful information to predict outcomes. This information can complement hormone and adrenocorticotrophic hormone (ACTH) stimulation assays.

Influence of aerobic exercise on maternal lipid levels and offspring morphometrics.

BACKGROUND: Maternal BMI, lipid levels (cholesterol, triglyceride, LDL, HDL), and exercise amount are interrelated and each influence offspring body size. This study proposed to determine the influence of exercise on maternal lipid levels and infant body size. METHODS: We had 36 participants complete these measures. Participants in the aerobic exercise intervention (n = 14) completed three 50-min sessions weekly from 16 weeks gestation to delivery and were compared with a non-exercise control group (n = 22). Maternal lipid profiles were assessed at 16 and at 36 weeks gestation. Fetal body size was measured at 36 weeks gestational age using ultrasound assessment. Neonatal body size measures were acquired from birth records. Statistical analysis included two-sample t-tests, correlations, and regression models. RESULTS: Participants were similar in age, pre-pregnancy BMI, gravida, parity, education, and gestational weight gain (GWG). There were no differences in gestational age, Apgar scores at 1 and 5 min for infants of exercisers relative to controls. Exercisers had higher pre-training triglycerides (p = 0.004) and pregnancy change in triglycerides (p = 0.049) compared to controls. Head circumference was significantly larger in exercise exposed infants relative to infants of controls. Pregnancy METs had a positive relationship with birth length (r = .445, p = .006) and birth weight (r = .391, p = .02). GWG had a moderate, positive relationship with fetal abdominal circumference (r = .570, p = .004). Regression analysis indicated 5 predictors explained 61.7% of the variance in birth weight (Adj.R2 = 0.469, F(5,13) = 5,13, p = 0.02); it was found that pregnancy METs (ß = .724, p = .007), 36 week cholesterol (ß = 1.066, p = .02), and 36 week LDL (ß = -1.267, p = .006) significantly predict birth weight. Regression analysis indicated 4 predictors explained 43.8% of the variance in birth length (Adj.R2 = 0.306, F(4,17) = 3.32, p = 0.04); it was found that pregnancy METs (ß = .530, p = .03), and 36 week LDL (ß = -.891, p = .049) significantly predict birth length. CONCLUSION: The primary association and predictors of infant body size was related to pregnancy exercise and late pregnancy cholesterol and LDL levels. Considering these relationships, it is essential that women maintain aerobic exercise during pregnancy, but should also be cognizant of lipid levels during their pregnancy. Therefore intervention during pregnancy focused on infant body size should involve exercise and and quality nutritional intake foods during pregnancy.