Screening for gestational diabetes mellitus (GDM) The American Diabetes Association’s (ADA) “2014 Standards of Medical Care for Diabetes”, published in the January 2014 supplement of Diabetes Care, notes a policy shift in screening for gestational diabetes mellitus (GDM), recommending a one-step or A two-step approach to GDM screening is recommended. The ADA has previously supported and recommended the one-step approach to screening for GDM as revised by the International Diabetes and Pregnancy Study Group (IADPSG) in 2010, and in the new guidelines, the ADA states that there is insufficient evidence to support the one-step approach over the two-step approach recommended by the National Institutes of Health (NIH) in March 2013. Here is a description of these two screening methods, which I don’t plan on being pregnant again anyway, written for those who need them. GDM two-step diagnostic method: the initial screening is a 50g glucose load test at 24-28 weeks of gestation, i.e., 50g of glucose is taken orally, and blood glucose is drawn and tested 1h later, and blood glucose level ≥ 7.8mmol/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 1h, 2h and 3h after load are measured respectively. Two or more abnormalities can confirm the diagnosis of GDM. One-step diagnosis method of GDM: the diagnostic threshold is FBG level 5.1mmol/L, 1h blood glucose 10.0mmol/L and 2h blood glucose 8.5mmol/L after taking 75g OGTT at 24-28 weeks of gestation, and no longer test 3h blood glucose, blood glucose value exceeding any of the above indicators can be diagnosed as GDM.