Determinants of Gestational Weight Gain in Obese Pregnant Women

The purpose of this study is to measure energy intake and energy expenditure during and after pregnancy. The investigators hypothesize that obese pregnant women with weight gain above the Institute of Medicine (IOM) guidelines, 'High Gainers', will have increased energy intake but no evidence for changes in energy expenditure after adjustment for the weight gained when compared to women with appropriate gestational weight gain, 'Normal Gainers'. Additionally, the investigators will measure the babies born to the pregnant women enrolled in MomEE at one time point before 10 days of life.