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.R-2 = 0.469, F(5,13) = 5,13, p = 0.02); it was found that pregnancy METs (beta = .724, p = .007), 36 week cholesterol (beta = 1.066, p = .02), and 36 week LDL (beta = 1.267, p = .006) significantly predict birth weight. Regression analysis indicated 4 predictors explained 43.8% of the variance in birth length (Adj.R-2 = 0.306, F(4,17) = 3.32, p = 0.04); it was found that pregnancy METs (beta = .530, p = .03), and 36 week LDL (beta = -.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.