Folic acid needs to be taken for three months during preparation for pregnancy and continued for the first three months after pregnancy. Folic acid has a clear role in preventing neural tube malformations in the fetus, so women need to take oral folic acid tablets during the preparation period and the first trimester of pregnancy. Folic acid tablets are 0.4mg tablets in size, usually women can take one tablet a day during preparation and pregnancy. For those who are at high risk of folic acid gene metabolism, 0.8mg can be taken under the supervision of a doctor, and should be taken throughout pregnancy. The amount of folic acid that a pregnant woman receives from food is not enough for her fetus, and she needs to take additional medication to supplement it. Folic acid tablets are beneficial to the growth and development of the fetus, and can effectively prevent neural tube malformations and reduce anencephaly and spina bifida in the fetus. Adverse reactions during oral administration of folic acid tablets are rare, and allergic reactions are rare. However, gastrointestinal symptoms such as nausea and bloating may occur with long-term use.