Should the IADPSG criteria be applied when diagnosing early-onset gestational diabetes?

To investigate whether the broad interpretation of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria with application to the early pregnancy, which is adopted as the standard in Japan, is appropriate.

We conducted this investigation by comparing diabetes-related adverse pregnancy outcomes among women treated for gestational diabetes mellitus (GDM) following an early-pregnancy diagnosis (early-onset GDM, n = 528) and those treated for GDM following a mid-pregnancy diagnosis, which is the international standard (Mid-term-onset GDM, n = 147).

Gestational weight gain was significantly lower in the early-onset GDM group (7.5 kg) than in the mid-term-onset GDM group (8.4 kg). The frequency of hypertensive disorders of pregnancy tended to be lower in the early-onset GDM group (5.6% vs. 8.8%, p = 0.085), but infant birth weight did not differ significantly between the groups. No between-group difference was observed in macrosomia, large-for-gestational-age (LGA), small-for-gestational age (SGA), low Apgar score, shoulder dystocia, cesarean delivery, NICU admission, hyperbilirubinemia, neonatal hypoglycemia, or respiratory distress syndrome. The frequency of LGA showed a significant association with pre-pregnancy body mass index, but did not differ according to the timing of therapy initiation.

We could not find the effectiveness of therapeutic interventions initiated after GDM diagnosis in the early pregnancy based on the IADPSG criteria, compared with therapeutic interventions after a mid-pregnancy GDM diagnosis. It was suggested that the IADPSG criteria for diagnosing GDM at 24-28 weeks' gestation should not be applied to Japanese women in the early pregnancy by a broader interpretation.