Gestational diabetes: update on screening, diagnosis and maternal management

Gestational diabetes is common and increasing in prevalence in Australia. New Australasian consensus recommendations released in June 2025 include higher diagnostic thresholds for gestational diabetes and guidance on early pregnancy screening. Women with risk factors for hyperglycaemia in pregnancy are recommended to have glycated haemoglobin (HbA1c) measured in the first trimester. Women with a previous history of gestational diabetes or a first-trimester HbA1c of 6.0 to 6.4% should undergo a pregnancy oral glucose tolerance test (POGTT) before 20 weeks gestation. All pregnant women without early gestational diabetes or existing diabetes should undergo a POGTT at 24 to 28 weeks gestation. Insulin remains the mainstay of pharmacological therapy. Metformin may have a role, but its use should be evaluated on an individual basis. Other non-insulin antihyperglycaemic therapies are contraindicated in pregnancy. Gestational diabetes is a significant risk factor for the development of type 2 diabetes and cardiovascular disease, and long-term surveillance is indicated.