The cost of a folic acid blood test is about$330, and the fee will vary from hospital to hospital and from region to region. Folic acid blood test is mainly to understand the bioavailability of folic acid, which can provide a basis for taking oral folic acid before and during pregnancy. It is recommended to take the test in the first 3 months of pregnancy, and based on the test results, the amount and duration of folic acid should be decided. The results of the folic acid test are generally categorized as mild risk, moderate risk and severe risk. Mild risk requires 0.4mg of oral folic acid 3 months before pregnancy, and 0.4mg of oral folic acid during the first 12 weeks of pregnancy, which can be stopped at the end of the 12 weeks and supplemented with folic acid from food. Moderate risk take 0.4mg of oral folic acid 3 months before pregnancy, 0.8mg of oral folic acid after pregnancy, take until the end of the 12th week of pregnancy to change to 0.4mg, take until the full term of pregnancy. Severe risk requires oral folic acid 0.8mg in the first 3 months of pregnancy, and continue to take oral folic acid 0.8mg after pregnancy, change to 0.4mg at the end of the 12th week of pregnancy, and take it until the end of the first trimester. The main purpose of taking folic acid is to prevent the occurrence of neural tube malformation in the fetus.