In this protocol, Ramsey reviews the health implications of obesity for mother and fetus. The incidence of obesity in the United States has increased dramatically. Of pregnant women in the country, more than half are overweight or obese and 8% or more are extremely obese. As the author notes, excessive gestational weight gain, particularly in women who are already overweight or obese, increases risk of maternal complications such as diabetes, hypertension, and operative deliveries and neonatal outcomes such as macrosomia and stillbirth.