When does gestational diabetes require a glucose tolerance test?

Pregnant women in 24-28 weeks of pregnancy, need routine screening for diabetes, to 75 grams of glucose into 300-400 ml of water, drink within five minutes, from the first drink of sugar water to calculate the time, one hour, two hours, and fasting blood draw three times, any one of which exceeds the normal range, can be diagnosed as gestational diabetes. once diagnosed, gestational diabetes should be treated immediately, otherwise it may cause complications for the pregnant woman and the fetus.