Propensity for excess gestational weight gain in African-American women may be explained by hypometabolic factors in early pregnancy

Background Women with obesity are at increased risk for excess gestational weight gain. Studies in non-pregnant women suggest that the etiology of weight gain may be different between African-American and White women and this may cause higher retention of weight postpartum and the increased prevalence of obesity in offspring. Objective To conduct a cross-sectional study in African-American and White pregnant women to identify metabolic and behavioral risk factors for aberrant weight gain trajectories. Design Metabolic and behavioral phenotyping was conducted in 66 pregnant women with obesity, expecting a single fetus, between 14 and 16 weeks of gestation. Energy expenditure was measured in free-living conditions over 7 days using stable isotopes and during sleep in a room calorimeter. Body composition was measured by air displacement plethysmography and physical activity by SenseWear™ accelerometers. Fasting blood was collected to measure markers of metabolic health. Results African-American (AA, n=34) an...