Objective:To compare the influences of two different diagnostic criteria of Gestational Diabetes Mellitus (GDM) on detection rates and pregnancy outcomes. Methods:More than ten thousand cases of pregnant women undergoing glucose screening and delivery in Nanjing Maternal and Child Health Care Hospital were enroll in this study and divided into two groups. One group was diagnosed according to the criteria in 7th edition of “Obstetrics and Gynecology”,and the other group was diagnosed according to the criteria of International Diabetes and Pregnancy Study Group (International Association of Diabetes and Pregnancy Study Groups,the IADPSG). We compared the GDM detection rates,mode of delivery,common complications of pregnancy and neonatal complications incidence between the two groups. Results:The GDM detection rate of IADPSG group was significantly higher than that of the 7th edition of “Obstetrics and Gynecology” group (P < 0.05). The cesarean section rate of IADPSG diagnostic criteria was significantly lower than the those of 7th edition of “Obstetrics and Gynecology” group (P < 0.01). The incidences of polyhydramnios and premature rupture of membranes were significantly lower than those of the 7th edition of “Obstetrics and Gynecology” group (P < 0.05). There were no significant differences of the incidences of hypertensive disorders on pregnancy,diabetes ketoacidosis,fetal distress and postpartum hemorrhage between two groups(P > 0.05). The incidences of fetal macrosomia,neonatal hypoglycemia and neonatal respiratory distress syndrome polyhydramnios were significantly lower than those of the 7th edition of “Obstetrics and Gynecology” group (P < 0.05). There were no significant differences of the incidences of premature birth,low birth weight infants,neonatal asphyxia,neonatal jaundice,neonatal hyperbilirubinemia,neonatal developmental malformations between two groups (P > 0 05). Conclusion:The diagnosis of GDM according to the IADPSG criteria can effectively elevate the detection rate of GDM,dramatically reduce the incidences of polyhydramnios,premature rupture of membranes and fetal macrosomia,thereby reducing the rate of cesarean section,and significantly reduce neonatal hypoglycemia and newborn respiratory distress and improving maternal and neonatal outcomes.