Although obesity screening and treatment are recommended by the US Preventive Services Task Force, 1 in 5 women are obese when they conceive. Women are at risk for complications of untreated obesity particularly during the reproductive years and may benefit from targeted screening. Risks of obesity and potential benefits of intervention in this population are well characterized. Rates of adverse pregnancy outcomes including gestational diabetes, preeclampsia, cesarean delivery, and stillbirth increase as maternal body mass index increases. Offspring risks include higher rates of congenital anomalies, abnormal intrauterine growth, and childhood obesity. Observational data suggest that weight loss may reduce risks of obesity-related pregnancy complications. Although obesity screening has not been studied in women of reproductive age, the effect of obesity and the potential for significant maternal and fetal benefits make screening of women during the childbearing years an essential part of the effort to reduce the impact of the obesity epidemic.