The impact of implementing the WHO-2013 criteria for gestational diabetes mellitus on its prevalence and pregnancy outcomes: A comparison of the WHO-1999 and WHO-2013 diagnostic thresholds

Aims/hypothesis: To determine the impact of implementing the new WHO-2013 criteria on prevalence of gestational diabetes mellitus (GDM) and pregnancy outcomes compared to the WHO-1999 criteria. Methods: A retrospective study conducted in pregnant women who were referred to the Erasmus MC for an oral glucose tolerance test (OGTT) between 2010 and 2015. Results: Of 3089 women, 11.5 % (n = 354) were diagnosed with GDM based on the WHO-1999 criteria and 17.0 % (n = 524) based on the 2013-criteria, with 97 (3.1 %) reclassified as non-GDM and 267 (8.6 %) reclassified as GDM when shifting from the 1999 to 2013-criteria. In contrast to 60 % of patients in the WHO-2013 group, only 2 % of the WHO-1999 group was diagnosed with GDM because of an elevated fasting glucose only. Patients reclassified as GDM by WHO-2013 criteria had a higher body mass index (p < 0.001) and delivered babies with a higher birth weight (p = 0.01). Maternal and neonatal adverse outcomes were comparable between patients with GDM based on WHO-1999 criteria and patients newly included by WHO-2013 criteria. Conclusions: Implementing the new diagnostic criteria leads to a considerable increase of prevalence of GDM. The newly included patients were more frequently overweighed and delivered babies with a higher birth weight. The added diagnostic value of the fasting glucose threshold of the WHO-1999 criteria is very low compared to the 2-h post-OGTT threshold, supporting the use of a lower fasting glucose threshold value as advocated by the WHO-2013 criteria. Tweet: The new WHO-2013 criteria leads to a considerable increase of prevalence of GDM. (C) 2019 Published by Elsevier B.V.