Diagnosis. The 3-h OGTT is performed on all patients who have an abnormal
screening test. Definitive diagnosis is based on an abnormal 3-h 100-g OGTT
performed after an overnight fast. Four glucose values are obtained.
and no further OGTT testing is needed.Normal pregnant values are FBS <95 mg/dL, 1 h <180 mg/dL, 2 h <155
mg/dL, 3 h <140 mg/dL. If only one value is abnormal, impaired glucose
tolerance is diagnosed. If ≥2 values are abnormal, GDM is diagnosed.
If FBS ≥125, overt diabetes is diagnosed and the 100-g glucose load should
not be given.