In 2010, The IADPSG published their revised GDM testing protocol based on the Hyperglycemia and Adverse Pregnancy Outcome Study. The Hyperglycemia and Adverse Pregnancy Outcome Study clarified the association between levels of maternal glucose with perinatal outcomes. The primary outcomes of the study examined infant birth weight, vaginal delivery or cesarean section, neonatal hypoglycemia, and fetal hyperinsulinemia and found an strong association between maternal glucose and birth weight above the 90th percentile and fetal hyperinsulinemia. IADPSG recommends a one-step approach to screening, using a threshold 1 abnormal value after a 75 g glucose challenge. All patients must be fasting for the one-step approach. The prevalence of GDM with this approach is approximately 15%–40%. The ADA adopted the IADPSG recommendations in 2011.