One-Step StrategyThe IADPSG defined diagnostic cut pointsfor GDM as the average fasting, 1-h, and2-h PG values during a 75-g OGTT inwomen at 24–28 weeks of gestationwho participated in the HAPO study atwhich odds for adverse outcomes reached1.75 times the estimated odds of theseoutcomes at the mean fasting, 1-h, and2-h PG levels of the study population.This one-step strategy was anticipated tosignificantly increase the incidence ofGDM (from 5–6% to 15–20%), primarilybecause only one abnormal value, nottwo, became sufficient to make the diagnosis(63). The anticipated increase inthe incidence of GDM could have a substantialimpact on costs and medical infrastructureneeds and has the potentialto “medicalize” pregnancies previouslycategorized as normal. Nevertheless,the ADA recommends these diagnosticcriteria with the intent of optimizinggestational outcomes because these criteriawere the only ones based on pregnancyoutcomes rather than end pointssuch as prediction of subsequent maternaldiabetes.