Comparative analysis of current diagnostic criteria for gestational diabetes mellitus

Background: To compare current guidelines for diagnosis of gestational diabetes mellitus (GDM) and to identify the ones that are the most relevant for application among pregnant Bulgarian population. Methods: A total of 800 pregnant women at high risk for GDM underwent 75 g oral glucose tolerance test between 24 and 28 weeks of gestation as antenatal screening. The results were interpreted and classified according to the guidelines of the International Association of Diabetes and Pregnancy Study Groups (IADPSG), American Diabetes Association (ADA), Australasian Diabetes in Pregnancy Society, Canadian Diabetes Association, European Association for the Study of Diabetes, New Zealand Society for the study of Diabetes and World Health Organization. Results: The application of different diagnostic criteria resulted in prevalences of GDM between 10.8% and 31.6%. Using any two sets of criteria, women who were classified differently varied between 0.1% and 21.1% (P, 0.001). The IADPSG criteria were the most inclusive criteria and resulted in the highest prevalence of GDM. There was a significant difference in the major metabolic parameters between GDM and control groups, regardless of which of the diagnostic criteria applied. GDM diagnosed according to all criteria resulted in increased proportion of delivery by caesarean section (CS). However, only ADA and IADPSG criteria identified both increased macrosomia (odds ratio, 2.36; 2.29) and CS rate. Conclusion: The need for GDM screening is indisputable. In our view, the new IADPSG guidelines offer a unique opportunity for a unified national and global approach to GDM.