Glucose tolerance test is usually performed at 24-28 weeks after pregnancy to monitor blood glucose values on fasting, 1 hour and 2 hours after drinking sugar water. 1 of the 3 items is abnormal to determine gestational diabetes. The defined values of blood glucose on fasting, 1 hour and 2 hours after taking sugar are 5, 1mmol/L, 10, 0mmol/L, 8, 5mmol/L respectively. different from Down’s screening at 15-20+6 weeks. Precautions before the glucose tolerance test: Eat normally 3 days before the test: To ensure an error-free diagnosis, you should not intentionally reduce the amount of food you eat before undergoing the test. You should eat as usual for the first 72 hours, without excessive intake of sweets and fruits, and your carbohydrate intake should not be less than 150 grams. Make sure to fast before the test: You should fast for 8-14 hours before the test, and you can drink water. Who is prone to gestational diabetes? 1. Advanced maternal age; 2. Previous gestational diabetes; 3. History of delivery of a huge baby; 4. People with hypertension or overweight; 5. Women with first-degree relatives with diabetes; 6. Excessive weight gain during pregnancy; 8. Ultrasound suggestive of excessive amniotic fluid during pregnancy.