Gestational diabetes: evolving diagnostic criteria

Purpose of review Gestational diabetes mellitus (GDM) is a common complication of pregnancy. There has been controversy and debate about how to optimally diagnose GDM and whether treatment modifies outcomes. We review the current controversies in both the screening and diagnosis of GDM and the benefits of treating GDM. Recent findings Three major studies have been published in the past 2 years that have evaluated these issues. The goal of the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study was to determine the level of maternal glycemia at which adverse fetal/neonatal or maternal outcomes are impacted. Rather than a definitive cut-off, the study found that there was a continuous relationship between maternal glycemia and pregnancy outcomes. Two studies evaluated the effect of treating mild GDM on both maternal and neonatal outcomes. Each found a significant benefit with diagnosis and treatment. Summary Ideally, the results of the HAPO study will bring order to the current international confusion surrounding the diagnosis of GDM. Recently, the International Association of Diabetes and Pregnancy Study Groups recommended new screening criteria for GDM based on the HAPO study. Professional organizations around the world are currently considering these recommendations.