Physical Activity and Maternal and Neonatal Metabolic Outcomes in Obese Pregnant Women

Abstract

Maternal obesity and physical inactivity during pregnancy are independently associated with unfavorable maternal and neonatal metabolic outcomes. Previous research in non-gravid adults suggests physical activity provides protection from many chronic diseases irrespective of body weight. PURPOSE: To determine if maternal and neonatal markers of metabolic health are better in physically active obese women versus sedentary obese women during pregnancy. We hypothesize that physically active obese pregnant women will have higher insulin sensitivity, lower oxidative stress levels, lower inflammatory markers, lower blood lipids, and will deliver leaner neonates with higher insulin sensitivity compared to their sedentary obese counterparts. METHODS: Lean (LG) (n=14), obese (OBG) (n=11), and obese-physically active (OPAG) (n=11) pregnant women were compared late in their 3rd trimester. Body composition, physical fitness level (YMCA cycle test), and weekly physical activity levels (accelerometry) were assessed. Maternal plasma markers of insulin sensitivity (HOMA-IR), oxidative stress, inflammation, and lipemia were measured at baseline, during a 30-minute bout of moderate intensity exercise, and during a 1-hour recovery period. Cord blood was collected at delivery for measurement of neonatal plasma insulin sensitivity, oxidative stress, inflammation, and lipemia. Infant body composition was measured 24-48 hours postpartum. RESULTS: The OPAG spent more time in moderate physical activity (17.4%) compared to the OBG (10.3%, p<0.001) and the LG (14.1%, p=0.04). The OPAG had higher predicted fitness levels (33.6±6.2ml/kg/min) compared to the OBG (26.1±3.8ml/kg/min, p=0.001) and the LG (29.2±4.0 ml/kg/min, p=0.12). Baseline C-reactive protein levels were higher in the OBG (8.3±4.7mg/dL) compared to the LG (2.4±2.0mg/dL, p<0.001) and the OPAG (5.6±1.8mg/dL, p=0.04). Cord blood free fatty acid concentration was lower in the OPAG (0.10 ±0.05meq/L) compared to both other groups (LG: 0.18±0.08meq/L, p=0.02; OBG: 0.18 ±0.06meq/L, p=0.04). Similar trends are emerging for other outcomes. CONCLUSION: Preliminary data suggests physical activity during pregnancy in obese women may improve maternal and neonatal metabolic health.