Variation in gestational diabetes diagnosis and care practices in maternity services in three high-income countries; a cross-sectional survey

There is limited international consensus about best diagnostic and care practices for gestational diabetes mellitus (GDM). This impacts consistency of care and perinatal outcomes. We aimed to explore GDM diagnostic and care practices in the UK, Ireland and Australia to better understand these variations and determine areas for improvement. We conducted a cross-sectional survey of healthcare professionals between August 2021-November 2022. The survey evaluated the use of GDM guidelines, associated diagnostic practices and post-diagnostic care. Data were descriptively analysed. Sixty-three maternity centres were represented (35 England and Wales, 12 Ireland, 16 Australia). 94% of centres in England and Wales and Australia respectively used their national guidelines to select women for GDM testing, with a wider variety of guidelines used in Ireland. Over 80% of centres across countries test women for GDM based on risk-factors identified in early pregnancy. At 24–28 weeks’ gestation, 94% of Australian centres used universal screening as per national guidelines, compared with 3% of centres in England & Wales, and 50% in Ireland, where universal screening is not included in national guidelines. Risk factors used to select women for screening varied between countries and between centres within countries at both time points, with some centres using risk factors outside of their national guidelines. Diagnostic tests for GDM varied between countries and between centres within countries, and according to gestation and previous GDM. Insulin was the most common first-line treatment in Australia, whereas in Ireland and England and Wales it was Metformin. Birth was planned at differing gestations according to centre and country, and according to management strategy. GDM-related practices vary within and between Australia, Ireland and England and Wales. National guidelines are not adhered to in some centres, which could result in inconsistent care within countries, and could result in inequitable perinatal outcomes. Further research should address standardised, evidence-informed care and guideline implementation barriers.