In 2010, national guidelines were published in Ireland recommending more sensitive criteria for the diagnosis of Gestational Diabetes Mellitus (GDM). The criteria were based on the 2008 Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) Study and were endorsed subsequently by the World Health Organization (WHO). Screening nationally is selective based on risk factors. We examined the impact of the new criteria on hospital trends nationally for GDM over the 10 years 2008–17.

Data from three national databases, the Hospital Inpatient Enquiry System (HIPE), National Perinatal Reporting System (NPRS) and the Irish Maternity Indicator System (IMIS), were analyzed using descriptive statistics, analysis of variance, and Poisson loglinear modelling.