The need for fasting for the 28-week pregnancy checkup depends on the items to be examined, some of which require fasting and some do not. Pregnant women need to know clearly before the maternity checkup, so as to avoid not fasting before doing the checkups that require fasting, which will affect the results. In general, during the 28-week checkup, blood pressure, pulse and weight are checked, and the uterine height and abdominal circumference of the pregnant woman are also measured, and urine routine is done. The fetal 3D ultrasound usually does not require fasting either, but the pregnant woman should not eat too much. However, if glucose tolerance test, thyroid function, liver and kidney function, trace elements and other tests need to be done, fasting is required. In general, the 75g glucose tolerance test must be done on an empty stomach and requires fasting from food and water for more than 8 hours. If the 75g glucose tolerance test is done and the pregnant woman is found to have normal blood sugar, she can have regular maternity checkups without special intervention. If the 75g glucose tolerance test is found to be abnormal, gestational diabetes can be diagnosed, requiring the pregnant woman to eat a low-carbohydrate diet and also to control and lower her blood sugar through appropriate exercise. In addition, if a pregnant woman has abnormal thyroid function, she needs to recheck thyroid function every month; if a pregnant woman has nausea, vomiting, anorexia, abdominal pain, jaundice and other symptoms, suggesting that there may be abnormal liver function; if a pregnant woman has a clear calcium deficiency in the previous pregnancy test or has calcium deficiency symptoms such as leg cramps in the middle of the night and bone and joint pain at the root of the thigh, she has to do a trace element test, and all of these maternity tests require fasting. Pregnant women can consult the corresponding hospital 2 days before the maternity checkup which items require fasting, and if there are items in the maternity checkup that require fasting, it is recommended to go to the maternity checkup as early as possible to avoid fasting for too long and causing hypoglycemia or even coma. You can prepare some snacks to replenish your energy in time after the blood draw. Try to wear loose clothes during the maternity checkup, and it is best to eat a light diet 3 days before the checkup to avoid excessive greasiness.