The Glucose Challenge Test (GCT) is a blood test used to screen for gestational diabetes, a temporary form of diabetes that can develop during pregnancy. During the GCT, a woman is given a sweet drink containing 75 grams of glucose, and her blood sugar level is measured one hour later. The test is typically done between 24 and 28 weeks of pregnancy and is used to identify women who may be at risk of developing gestational diabetes. A high blood sugar level after one hour may indicate that further testing is needed to confirm a diagnosis of gestational diabetes. The GCT is a relatively simple and non-invasive test that can help identify gestational diabetes early, allowing for prompt treatment to manage blood sugar levels and reduce the risk of complications for both mother and baby.