Pregnancy outcomes of Chinese women with gestational diabetes mellitus defined by the IADPSG's but not by the 1999 WHO's criteria.

Objective: To compare pregnancy outcomes of women with gestational diabetes mellitus (GDM) newly defined by the International Association of Diabetes and Pregnancy Study Group (IADPSG)'s criteria vs GDM cases missed by a shift from the 1999 World Health Organization (WHO)'s criteria to the IADPSG's.

Methods: From 2010 to 2012, we recruited 17 808 women who registered within 12 weeks of gestation in Tianjin, China. All women underwent a 50-g 1-h glucose challenge test (GCT) at 24-28 weeks of gestation and further underwent a 75-g 2-h oral glucose tolerance test (OGTT) if the GCT result was ≥7·8 mmol/l. Women were divided into four groups, i.e., GDM defined by both criteria, GDM defined by the IADPSG's only, GDM defined by the 1999 WHO's only and non-GDM by either of them. Large for gestational age (LGA), macrosomia, pregnancy-induced hypertension (PIH) and preterm birth were compared among the four groups. Logistic regression was used to control for confounders.

Results: The use of IADPSG's and the 1999 WHO's criteria detected that 7·7% (n = 1378) and 6·8% (n = 1206) of women had GDM, respectively, with 429 GDM newly identified and 257 women missed by a shift from the 1999 WHO's to the IADPSG's. The IADPSG's newly defined GDM had significantly increased risks of LGA (adjusted OR: 2·23, 95%CI: 1·36-3·64) and macrosomia (2·65, 95%CI: 1·50-4·66) than the 1999 WHO's only defined GDM cases.

Conclusions: A shift of the 1999 WHO's criteria to the IADPSG's diagnosed more GDM cases who had worse pregnancy outcomes than those cases missed.