['To determine the impact of the new 2013 World Health Organization (WHO) criteria for gestational diabetes mellitus (GDM) diagnosis on GDM prevalence and pregnancy outcomes in Asian ethnic groups compared to the 1999 WHO criteria.', 'A retrospective cohort study included 855 pregnant females of Chinese, Malay, and Asian Indian ethnicity at high risk of GDM who underwent 75-g oral glucose tolerance tests (OGTTs) between July 2008 and June 2010 in a tertiary center in Singapore. GDM prevalence, reclassification, and pregnancy outcomes were determined using the 2013 and 1999 diagnostic cutoffs for fasting and 2-hour postglucose (PG) values.', 'The prevalence of GDM was reduced from 28.8% to 21.1% when the 2013 criteria were used. Overall, 10.2% subjects were reclassified from GDM to normal using the 2013 criteria, and 2.6% were reclassified from normal to GDM, giving a net reclassification rate of 12.8%. Reclassification from GDM to normal was greatest among Chinese, followed by Asian Indians, but the prevalence rate was unchanged among Malays. Babies of mothers who were reclassified from normal to GDM were more likely to have birth weight >95th centile and shoulder dystocia.'] Is the Prevalence of Gestational Diabetes Mellitus Among Asian Females Lower Using the New 2013 World Health Organization Diagnostic Criteria?