This study plans to learn more about how triglyceride levels in pregnancy affect newborn fat mass. Obesity in pregnancy, in the absence of gestational diabetes, is now the most common cause of large-for-gestational-age infants and increased newborn fat mass. Previous data supports the idea that maternal triglycerides, not glucose, are the strongest predictor of both total newborn fat mass and liver fat. In this study, mothers will monitor triglyceride and glucose levels at specific points in pregnancy using point-of-care meters at home. Two weeks after birth, infants will have total fat measured by air-displacement plethysmography (PEAPOD) and liver fat measures by Magnetic Resonance Spectroscopy (MRS). The central hypothesis is that in obesity, fasting triglycerides and postprandial triglycerides will predict newborn fat mass in a free-living environment.