The prevalence of gestational diabetes mellitus (GDM) may increase with the implementation of revised diagnostic criteria (as recommended by the International Association of the Diabetes and Pregnancy Study Groups) aimed at identifying pregnancies at increased risk of adverse perinatal outcomes. There are clear implications for health-care services in terms of resources and the associated cost-benefit relationship. Our study analysed the impact on endocrinology clinic visits, the initiation of insulin treatment and fetal and maternal outcomes.
A retrospective cohort study was conducted. The medical records of patients diagnosed with GDM referred to the Endocrinology Clinic were reviewed, comparing two 12 month periods: March 2012 to February 2013 (period 1) and March 2015 to February 2016 (period 2), before and after implementation of the new criteria. Maternal and fetal outcomes were analysed for six months of each period.
165 GDM patients attended the endocrinology clinic in period 1 vs 323 patients in period 2. Insulin treatment increased significantly in period 2, from 34.2% to 53.1% (p = 0.002). The mean number of Endocrinologist consultations (Medicare billed) increased from 3.6 to 4.2 (p = 0.006) and with a Diabetic Educator from 1.3 to 1.5 (p = 0.049). The rate of caesarean sections (CS) in patients with GDM increased from 31.1% to 47.0% (p = 0.038). The number of neonates grouped as ‘Small for Gestational Age’ (SGA) increased in insulin-treated patients in period 2 vs period 1 (17 vs 0, p < 0.001) but the number of ‘Large for Gestational Age’ neonates was similar (6 vs 5, p = 1).
This study has demonstrated that the new GDM diagnostic criteria have impacted on existing health-care resources with a corresponding increase in costs. Hospital systems will need to plan for the increased demands on pregnancy-related diabetes services.