Diagnosis of GDM by an oral glucose tolerance test
| Oral glucose load* | |||||||
|---|---|---|---|---|---|---|---|
| 100-g glucose† | 75-g glucose† | ||||||
| Fasting‡ | 95 mg/dl | 5.3 mmol/l | 95 mg/dl | 5.3 mmol/l | |||
| 1-h‡ | 180 mg/dl | 10.0 mmol/l | 180 mg/dl | 10.0 mmol/l | |||
| 2-h‡ | 155 mg/dl | 8.6 mmol/l | 155 mg/dl | 8.6 mmol/l | |||
| 3-h‡ | 140 mg/dl | 7.8 mmol/l | — | — | |||
Data are from Metzger et al. (9).
↵* The test should be performed in the morning after an overnight fast of at least 8 h but not more than 14 h and after at least 3 days of unrestricted diet (≥150 g carbohydrate/day) and physical activity. The subject should remain seated and should not smoke throughout the test.
↵† Two or more of the venous plasma glucose concentrations indicated below must be met or exceeded for a positive diagnosis.
↵‡ The cutoff values are those proposed by Carpenter and Coustan (10) for extrapolation of the whole blood glucose values found by O'Sullivan and Mahan (11) to plasma glucose concentrations.