In order to diagnose you with gestational diabetes, your doctor will order a test from the lab. There are two levels of the test that can be taken – the one hour glucose tolerance test and the three hour glucose tolerance test.
The one hour test involves taking a blood sample after you have fasted and then drinking a beverage high in glucose and testing your blood again one hour later. With the three hour version, you proceed the same except the drink has a higher concentration of sugar and your blood is tested each hour for three hours instead of one. The purpose of these tests is to see how your body reacts to and process the large amount of sugar in the drinks.
The American Diabetes Association lists the following blood glucose levels that would indicate gestational diabetes is present: