Establishing consensus in the diagnosis of gestational diabetes following HAPO: where do we stand?

New proposals for the diagnosis of gestational diabetes (GDM), promulgated by the International Association of Diabetes and Pregnancy Study Groups (IADPSG), will substantially increase the number of women diagnosed with GDM. This will have an enormous impact on healthcare resources, diverting attention away from genuinely high risk diabetic pregnancies. Randomized trials in 'mild' GDM indicate that the main effects of treatment are a 2 %-3 % reduction in birth weight, fewer 'big babies', and less shoulder dystocia. However, these studies used different diagnostic criteria, and women diagnosed by the broader IADPSG criteria may not derive the same modest benefit. Modeling indicates a very high cost per QALY, unless later development of type 2 diabetes can be prevented. Far from producing consensus, the IADPSG suggestion has thrown sharply into focus the need to assess critically the risks, costs and benefits of adopting criteria that may pathologize a large number of otherwise normal pregnancies.