Glucose tolerance test, color ultrasound, and routine blood and urine tests are performed at 25 weeks of pregnancy, and their roles are as follows. 1. Glucose tolerance test: Screening by glucose tolerance test can prevent other symptoms such as diabetes. When blood sugar is abnormal, if not effectively controlled in time, it can lead to hypertension during pregnancy, and even the risk of preterm birth, excessive amniotic fluid, giant baby, and fetal malformation will increase; 2, color ultrasound: color ultrasound is the basic item to exclude fetal malformation, to observe whether the fetal body and organs have developmental malformations, such as internal organs turned out, short limbs, Siamese twins and other abnormalities can also be detected, such as congenital heart disease, intestinal 3, blood routine: check white blood cells, hemoglobin, platelets, etc., which helps to understand whether the pregnant woman-to-be has infection, anemia, and normal coagulation function; 4, urine routine: mainly check whether the ketone body characterization and urine protein are normal, which helps to understand whether the pregnant woman has diabetes, insufficient energy intake, etc. It is recommended to control the intake of sugar and fruits in the days before the examination, eat a light diet, not to eat after 8 pm the night before, and ensure an empty stomach on the day of the examination.