Whether or not you need to fast for a blood draw at 38 weeks of pregnancy depends on the items to be checked, such as no fasting blood sugar, liver function, kidney function and other tests do not require fasting. Some hospitals will routinely check pre-admission tests in late pregnancy, such as blood analysis, urinalysis, coagulation mechanism, liver and kidney function, fasting blood glucose, viral screening, electrocardiogram and other tests, when this situation requires fasting. Fasting is not required for just routine blood analysis to assess the presence of anemia and other conditions. It is recommended that you ask your clinician which tests you would like to have done next time or if you would like to fast. For pregnant women between 37 and 41 weeks of gestation, mandatory checkups include ultrasound and fetal heart rate monitoring. The main purpose of ultrasound is to assess the size of the fetus, the amount of amniotic fluid, fetal position, and if necessary, to detect the umbilical artery blood flow; fetal cardiac monitoring is mainly to assess whether there is intrauterine hypoxia in the fetus. Fasting is not required for any of the above tests. In addition, the items to be included in each checkup are usually decided by the obstetrician after a comprehensive assessment based on clinical guidelines and the patient’s own condition, so whether to fast or not should follow the doctor’s instructions.