The NIH endorsed the two-step method as the diagnostic method for GDM in February 2013, and the American College of Obstetricians and Gynecologists (ACOG) also supports the adoption of this method, which is now commonly used in clinical practice in the United States for screening and diagnosis of GDM. The two-step diagnosis method of GDM: a 50g glucose load test is performed at 24-28 weeks of gestation for initial screening, i.e., 50g of glucose is taken orally, and blood glucose is drawn and tested 1h later, and blood glucose level ≥ 7.8 mmol/L is abnormal; abnormal cases need further 100g glucose tolerance test (OGTT) to confirm the diagnosis, and fasting blood glucose (FBG) and blood glucose levels at 1h, 2h and 3h after the load are measured respectively. The diagnosis of GDM is confirmed by two or more abnormalities. The IADPSG and the WHO support the one-step approach, which is more commonly used in Europe. The IADPSG believes that it is important to identify more patients with GDM, as the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study shows that a mild increase in maternal blood glucose levels increases the risk of adverse pregnancy outcomes and adverse neonatal outcomes. One-step diagnosis of GDM: The diagnostic threshold is FBG level 5.1mmol/L, 1h glucose 10.0mmol/L and 2h glucose 8.5mmol/L after 75g OGTT at 24-28 weeks of gestation, no more 3h glucose testing, and glucose values above any of these indicators can be diagnosed as GDM. However, Professor Grant emphasized that the HAPO study is an observational trial, and there is no evidence from randomized clinical trials that one-step or two-step GDM screening improves maternal and neonatal clinical outcomes. However, it is interesting to note that the IADPSG and NIH guideline writing groups came up with their own different recommendations after evaluating and reviewing the same data. The ADA did not feel it could decide which of these two expert consensus groups’ recommendations was more appropriate. Both recommendations are factually correct and both have value. More research is needed to further determine which of the two is better for improving maternal and neonatal clinical outcomes.