A pregnancy oral glucose tolerance test involves:
fasting overnight (for at least 8 hours)
initial blood test to test fasting glucose levels
drinking a syrupy glucose solution containing 75 grams of glucose
have a blood glucose test at 1 hour after drinking the glucose solution
have a final blood glucose test 2 hours after drinking the glucose solution
The diagnosis of gestational diabetes is confirmed on high sugar readings at any of the following time points:
fasting glucose value
1 hour glucose value
2 hour glucose value