Whats the 3 hr glucose test for gestational diabetes?

A Drink/Bloodwork: Some obs do this at their office, or you go to a lab. The test is done first thing in the morning after you have not eaten overnight. They draw your blood to check the "fasting" (pre-breakfast) blood sugar, then you drink a bottle of liquid with 75 grams of sugar. Blood is drawn at 1, 2, and 3 hours after the drink. If 2 of 4 levels are elevated then you'll be diagnosed with gestational diabetes.