Background: Impact of diagnosis and treatment of gestational diabetes (GDM) with the lower International Association of Diabetes in Pregnancy Study Groups (IADPSG) criteria, compared with the higher New Zealand criteria, on later maternal and child health remains unclear.
Methods: Women and their children from the GEMS Trial, who were randomised to GDM diagnosis using the lower or higher criteria, were assessed 5 years later using questionnaires and routinely collected data. The primary outcomes were maternal type 2 diabetes/prediabetes, and child body mass index (BMI) z-scores. Secondary outcomes included maternal cardiometabolic risks, child growth and neurodevelopment.
Results: Of 1026 eligible families, 869 mothers (72%) and 833 children (69%) participated. Maternal type 2 diabetes/prediabetes rates were similar between the lower versus higher criteria groups (20.5% versus 16.5%; adjusted relative risk (aRR) 1.27, 95% confidence interval [CI] 0.96-1.67; P=0.10). Child BMI z-scores were similar between groups (mean 0.36, standard deviation[SD] 1.32 versus 0.50 [SD 1.45], adjusted mean difference -0.15, 95% CI -0.34-0.05; P=0.14). Children in the lower criteria group compared to children in the higher criteria group were less likely to be overweight (4.9% versus 9.1%; aRR 0.53, 95% CI 0.31-0.91; P=0.02) or have a neurodevelopmental impairment (15.5% versus 22.1%; aRR 0.70, 95% CI 0.52-0.94; P=0.02). In subsequent pregnancies women in the lower criteria group had less hypertension but more GDM diagnosed.
Conclusions: GDM diagnosed by the lower IADPSG criteria compared to the higher New Zealand criteria resulted in similar rates of subsequent maternal diabetes diagnoses and child BMI 5 years later.