Introduction
Gestational diabetes mellitus (GDM) is defined as glucose intolerance first recognized during pregnancy, regardless of whether the condition started before pregnancy. The incidence of GDM has increased worldwide, and its clinical implications have been highlighted in the context of the rapid increase in the prevalence of early onset type 2 diabetes, especially for child-bearing women. 1–4 For decades, large clinical studies have focused on establishing diagnostic criteria that distinguish between GDM and healthy pregnancies.5–7 The International Association of Diabetes and Pregnancy Study Group 8 adopted the results of the Hyperglycemia and Adverse Pregnancy Outcome study 6 to diagnose GDM using a one-step 75-g oral glucose tolerance test (OGTT). This new criterion has been widely accepted by multiple guidelines; however, many of them, including the National Institutes of Health9 and American College of Obstetricians and Gynecologists, 10 still support the two-step approach.
The current guidelines for diabetes management recommend that all pregnant women not previously diagnosed with diabetes should be screened for GDM at 24–28 weeks of gestation. 1,11 GDM is closely associated with an increased risk of maternal complications, including preeclampsia, as well as perinatal fetal morbidities, such as macrosomia, large for gestational age (LGA), and preterm birth. It is also associated with a high risk of developing future type 2 diabetes and even mortality in affected women. 12,13
The serious health outcomes related to GDM inevitably raise the question of how to predict and manage adverse outcomes. We considered whether the outcome could be predicted using the results of the 100-g OGTT in affected individuals at the time GDM was diagnosed. Several previous studies have shown controversial results, probably due to the small number of study participants, different definitions of adverse pregnancy outcomes, or even ethnic differences, leaving this issue to be elucidated. 13-15
In view of this, we investigated how a 100-g OGTT result, obtained simultaneously with a GDM diagnosis, can be used to predict adverse pregnancy outcomes in a large survey of Korean pregnant women.