Abstract: The overweight and obesity are related with pregnancy induced hypertension， gestational diabetes mellitus，fetal macrosomia，cesarean section rate increased and thrombotic disease in pregnant women. Pre-pregnancy height，body mass and the increase of body weight during pregnancy are more important factors. Pregnancy obesity is increased year by year， with the adverse obstetric outcomes increasing，which has the significant effect on the occurrence of abnormal offspring，obesity，type 2 diabetes and other adult diseases. Summary of obesity with a variety of pregnancy complications and obstetric outcome relationship，suggests that control of body weight during pregnancy，screening pregnancy complications will help improve the quality of care during pregnancy，improving maternal and child outcomes for obese pregnant women to strengthen perinatal care and postpartum follow-up.

Key words: Pregnancy, Pregnancy complications, Obesity, Body weight, Body mass index