In these days overweight or obesity in women of reproductive age is rapidly increasing worldwide and they are more likely to gain excess weight during pregnancy. Overweight or obesity is considered as a common high-risk obstetric condition along with gestational diabetes, hypertensive disorder during pregnancy, operative delivery and poor fetal outcomes. Especially, obesity can predispose to the development of fetal macrosomia, which may lead to childhood obesity. Asian women have different characteristics of obesity than western women. This study presents the similarities and differences, between the Korean and Western obese women, in the maternal BMI and pregnancy outcomes including fetal macrosomia related to maternal weight gain. In addition, I will discuss the maternal management for better pregnancy outcomes in obese pregnant women.