The ACOG has consistently recommended universal screening for gestational diabetes between 24 and 28 gestational weeks. Although controversial, the ACOG does endorse earlier screening for GDM in patients with additional risk factors. But what about patients who present for prenatal care after the 28th or 29th week? Should screening for GDM be done in the 3rd trimester? And if we do screen in the then, what is the reference range for “normal “or “abnormal”? Is it the same interpretation as when it is done between 24 and 28 weeks? Does 3rd trimester screening impact parental outcome? In this episode, we will examine the data and provide a recommendation of when testing for gestational diabetes in the 3rd trimester may have the most impact.