Have Pregnancy Outcomes Improved with the Introduction of the International Association of Diabetes and Pregnancy Study Groups Criteria in Japan?

Aims/Introduction This study aimed to investigate the effects of the introduction of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria for diagnosing gestational diabetes mellitus (GDM) on maternal and neonatal outcomes in Japan. Materials and Methods This was a retrospective study carried out at a tertiary center in Japan. Previously in Japan, GDM was diagnosed if two or more of the following Japan Society of Obstetrics and Gynecology (JSOG) criteria were met: fasting plasma glucose >= 100 mg/dL, 1-h value >= 180 mg/dL or 2-h value >= 150 mg/dL on the 75-g oral glucose tolerance. Since 2010, GDM has been diagnosed if one or more of the following IADPSG criteria are met: fasting plasma glucose >= 92 mg/dL, 1-h value >= 180 mg/dL or 2-h value >= 153 mg/dL on the 75-g oral glucose tolerance. We compared the pregnancy outcomes of all pregnant women with singleton pregnancies after 22 weeks' gestation at our hospital before (JSOG period) and after (IADPSG period) the IADPSG criteria were adopted. Results There were 3,912 women in the JSOG period and 4,772 in the IADPSG period. GDM prevalence increased from 2.9% in the JSOG period to 13% in the IADPSG period (P < 0.001). No significant differences between the groups were found in rates of macrosomia, or large for gestational age, and no significant differences were found in birthweight. The neonatal hypoglycemia rate and neonatal intensive care unit admission rate were significantly lower in the IADPSG period (adjusted odds ratio 0.51 and 0.78, respectively). Conclusions Introduction of the IADPSG criteria for diagnosing GDM increased GDM diagnosis frequency fourfold, but reduced neonatal intensive care unit admission and neonatal hypoglycemia rates significantly.