In early pregnancy there is an increased risk of spontaneous abortion and congenital anomalies. In later gestation maternal metabolic manifestations of the metabolic syndrome, such as gestational hypertensive disorders and diabetes, become clinically recognized because of the insulin resistance in obese people. At parturition the obese patient is at an increased risk of cesarean delivery and associated complications of anesthesia, wound disruption, infection, and deep venous thrombophlebitis. For the fetus there are short-term risks of fetal macrosomia, more specifically obesity, and long-term risks of adolescent components of the metabolic syndrome.