O'Malley EG, et al. - Researchers conducted this prospective study among women who had maternal risk factors for GDM in order to compare different sets of diagnostic cut-off points on plasma glucose measurements following a 75g Oral Glucose Tolerance Test (OGTT). They conducted one-step OGTT at 26-28 weeks gestation in 202 women (139 (69%) with one risk factor for GDM and 63 (31%) with > 1). Among these women, 53% (n = 108) had GDM when WHO criteria were used vs 35% (n = 71) and 18% (n = 36) when using Canadian criteria and National Institute for Health Care Excellence criteria (NICE) criteria, respectively. Pharmacological treatment may be required for hyperglycemia control in 50% of the 108 women (n = 54). If the Canadian criteria or the NICE criteria were applied, hypoglycaemics would not have been provided to 11/54 (20.4%) women and 36/54 (66.7%) women, respectively. Women who had GDM based on the WHO criteria but who had a normal OGTT based on the Canadian or NICE criteria exhibit increased insulin resistance as evident by maternal insulin, HOMA-IR and C-peptide measured at the time of the OGTT. Under stringent research conditions, this work implies that the Canadian and, in particular, the NICE criteria did not lead to identification of women who may benefit from improved glycaemic control.