Excessive weight gain in pregnant women has become one of the important factors that harm mother′s health and cause adverse pregnancy outcomes. Excessive weight gain during pregnancy can increase the pregnancy complications and adverse pregnancy outcomes, such as macrosomia, which increase the rate of cesarean section. Excessive weight gain during pregnancy is not only a risk factor for short-term postpartum obesity and weight retention, but also increases the long-term risk of obesity and metabolic syndrome. This review summarizes recent studies on the relationship between maternal weight gain and the rate of cesarean section and postpartum weight retention, in order to highlight the importance of weight management in pregnancy.