This research project explores a crucial aspect of maternal and fetal health: the diagnosis of gestational diabetes mellitus (GDM), a condition that poses risks to both pregnant women and the babies. Gestational diabetes is a condition that can develop during pregnancy, characterized by dysglycemia and associated risks of complications such as pre-eclampsia, cesarean delivery, and macrosomia. For the baby, it raises the risk of developing obesity, type 2 diabetes later in life, and metabolic syndrome. Therefore, early and accurate diagnosis is paramount to manage and mitigate these risks. The IADPSG (International Association of Diabetes and Pregnancy Study Groups) criteria, the current standard for GDM diagnosis, has been widely adopted due to its putative sensitivity in detecting GDM and potential for reducing GDM-related complications. However, this method is not without its limitations, including the risk of over- or under-diagnosis of GDM. This project will investigate the efficacy of an alternative diagnostic method, the National Priorities Research Program (NPRP) criteria, against the conventional IADPSG criteria, diagnosis usually being undertaken between the 24th and 28th weeks of pregnancy. The NPRP criteria are based on a unified assessment of the oral glucose tolerance test (GTT), which could offer a four-level classification of dysglycemia in pregnancy as opposed to the binary diagnosis by the IADPSG criteria, thus having the added benefit of glycemic risk stratification during pregnancy. By comparing the outcomes of pregnancies diagnosed using the NPRP criteria against those diagnosed using the IADPSG criteria, the investigators aim to assess whether the NPRP criteria can provide improved outcomes (Bashir et al. 2021) in terms of maternal and fetal health through better informed GDM-related decision-making. In addition, this study proposes the NPRP criteria as potentially able to mitigate over- and under-diagnosis of GDM. This study will employ a parallel-group, prospective, randomized, pragmatic, controlled trial design and the study investigators will work closely with a cohort of pregnant women throughout pregnancy, employing both diagnostic methods to evaluate their impact on the health of the mother and the baby. The evaluation will not only focus on the immediate outcomes during pregnancy but will also aim to follow up on longer-term metabolic health implications for both mother and child post-delivery after the trial is completed and if the participant consents to such additional follow-up. The significance of this research lies in its potential to transform the current practices in GDM diagnosis, by offering evidence on the effectiveness and benefits of the NPRP criteria, thus paving the way for a shift towards a more patient-centered approach to the diagnosis of gestational diabetes. Determining if the NPRP criteria can lead to better health outcomes for mothers and babies can have profound implications for maternal and child health. Improved diagnostic methods could lead to more timely interventions, reducing the prevalence of complications associated with gestational diabetes and improving the quality of life for countless families. Through this study, the investigators hope to make a significant contribution to the well-being of pregnant women and babies, ensuring a healthier start for the next generation.