The cost of the glucose tolerance test, which costs about$50-60, is a blood test taken at 24-28 weeks of pregnancy. On the day before the glucose tolerance test, you should fast for 8-14 hours after dinner and have your blood drawn on an empty stomach once before 9:00 the next day. Then drink powdered sugar. Dissolve 75mg of powdered sugar in 300ml of water and finish it within 5 minutes. One hour and two hours after drinking the powdered sugar, venous blood was drawn for blood glucose testing. The normal values are 5.1mmol/L for fasting blood glucose, 10.0mmol/L for one hour after taking sugar, and 8.5mmol/L for two hours after taking sugar. if one of these values reaches or exceeds the normal value, gestational diabetes is diagnosed.