Diagnostic Criteria for Diabetes and Gestational Diabetes Mellitus

Standard Diagnostic Criteria

The American Diabetes Association recommends that the test should be performed in the morning after an overnight fast of at least 8 hours 1, 2
For standard diabetes diagnosis, a 75-g glucose load dissolved in water is administered, as recommended by the American Diabetes Association 1, 3
Blood samples are collected at baseline (fasting) and 2 hours after glucose consumption, according to the American Diabetes Association guidelines 1, 4
The diagnosis of diabetes is made when fasting plasma glucose is ≥126 mg/dL or 2-hour plasma glucose is ≥200 mg/dL, as defined by the American Diabetes Association 3, 4

The American College of Obstetricians and Gynecologists recommends performing a 75-g OGTT at 24-28 weeks of gestation in pregnant women not previously diagnosed with diabetes 2, 5
Blood samples are collected when fasting and at 1 and 2 hours after glucose consumption, as recommended by the American College of Obstetricians and Gynecologists 2, 6
The diagnosis of GDM is made when any of the following plasma glucose values are met or exceeded: fasting ≥92 mg/dL, 1 hour ≥180 mg/dL, or 2 hour ≥153 mg/dL, according to the American College of Obstetricians and Gynecologists guidelines 2, 5

The American Heart Association recommends that the test should be performed using venous plasma samples for standardization 8
For patients with conditions affecting red blood cell turnover, only plasma glucose criteria should be used, as recommended by the American Diabetes Association 1
A1C testing should be performed using a method certified by the National Glycohemoglobin Standardization Program (NGSP) and standardized to the Diabetes Control and Complications Trial (DCCT) assay, according to the American Diabetes Association guidelines 1, 3

The American College of Obstetricians and Gynecologists recommends that screening for GDM should occur at 24-28 weeks of gestation in pregnant women 2, 4
Women with GDM should be screened for persistent diabetes at 6-12 weeks postpartum, as recommended by the American Diabetes Association 7, 9
Women with a history of GDM should have lifelong screening for diabetes or prediabetes at least every 3 years, according to the American Diabetes Association guidelines 7, 9
The American Diabetes Association states that the efficacy of interventions for primary prevention of type 2 diabetes has primarily been demonstrated among individuals with impaired glucose tolerance (IGT) 1