This test is recommended to diagnose Gestational Diabetes in pregnant women who screen positive with 50 gm Glucose challenge test. At least two values must meet or exceed the stated reference value for a diagnosis of Gestational Diabetes mellitus (Fasting >95 mg/dL; 1 hour >180 mg/dL; 2 hours > 155 mg/dL; 3 hours>140 mg/dL). If results are normal in clinically suspected cases, test must be repeated in the third trimester.