From the literature, it is clear that overweight and obese pregnant women experience adverse pregnancy outcomes at higher rates than women of normal weight and that shifting of prepregnancy BMI upward from normal=underweight during successive pregnancies leads to greater risk of many adverse pregnancy outcomes. Our study did not find the shift in pre-pregnancy BMI from overweight to obese to be associated with increased risk for SGA, LGA, preterm birth, or hypertension in pregnancy. While there was a significant increase in the proportion of emergency cesarean sections, we did not identify any specific risk factor contributing to that increased risk. This was not totally unexpected as increased BMI is associated with decreased risk of SGA, and preterm birth and obese women have a moderate increased risk for unplanned cesarean section. Overweight N568 Normal=underweight