Abstract: Metabolic syndrome（MS） is characterized by various endocrine and metabolic abnormalities that are commonly seen in polycystic ovary syndrome （PCOS）. The incidence of MS is rising in the world，with a trend toward younger age. Aside from the increased risks of developing long-term complications such as cardio-cerebrovascular diseases and diabetes，those women with MS in reproductive age are prone to suffer from infertility，abortion and pregnancy complications. The abnormal maternal metabolic environment in those women with MS may exert negative effects on the offspring development at the early period of pregnancy. This article reviewed recent findings on how MS affected the oocyte quality and early-stage embryo development.

Key words: Metabolic syndrome X, Polycystic ovary syndrome, Oocytes, Overweight, Insulin resistance