Lay summary
Gestational diabetes (GDM), or diabetes in pregnancy, is a growing global health concern with long-term complications for both mothers and children. The best glucose thresholds for use in the test for diagnosing GDM remain uncertain. The GEMS trial demonstrated that diagnosing GDM with the lower glucose thresholds, commonly used internationally, compared to the higher New Zealand thresholds, reduced mothers’ pregnancy-related risks and improved newborn babies’ health. However, the long-term benefits and harms of either threshold are unclear. This project aims to determine whether GDM diagnosis with lower or higher thresholds affects the health of mothers and their children five years later. We will study 869 women who took part in the GEMS trial, and their children, using questionnaires and administrative health data. The findings will be used to help inform national guidelines for how GDM should be diagnosed to improve the health of women and children in Aotearoa New Zealand.