Impact of new diagnostic criteria for gestational diabetes

In January 2015, the diagnostic and therapeutic criteria for gestational diabetes changed, with the goal of increasing the sensitivity of diagnosis and improving overall glycemic control, and thus reducing adverse pregnancy outcomes. Our primary aim was to evaluate the effect of the new guidelines on the incidence of diagnosis of gestational diabetes and the incidence of therapeutic interventions. Our secondary aim was to look at the incidence of adverse pregnancy outcomes.

A retrospective clinical audit was conducted at a regional hospital to compare the incidence of gestational diabetes, and the specific maternal and neonatal outcomes before and after the change in guidelines was implemented. Data were collected via chart review for a 6-month period before and after the change in guidelines in January 2015. Data collected included demographics, neonatal and maternal outcomes, and the treatment type used for patients diagnosed with gestational diabetes.

There was a significant increase in the incidence of diagnosis of gestational diabetes (9.8-19.6%; P < 0.001), and an overall increase in the use of pharmacological treatments for gestational diabetes. There was no significant difference in the incidence of the adverse outcomes measured, including cesarean delivery and macrosomia. There was no significant change in mean fetal weight.

Despite a doubling of the incidence of diagnosis of gestational diabetes, and a consequent increase in pharmacological interventions, the change in diagnostic and therapeutic criteria did not significantly reduce the neonatal or maternal adverse outcomes measured.