Folic acid is a drug that must be taken orally in preparation for and during pregnancy, and taking folic acid can effectively prevent fetal neural tube malformations. Most pregnant women believe that it is sufficient to take folic acid during the first trimester of pregnancy and the first trimester of gestation. In fact, the amount of folic acid and the time of taking folic acid are not quite the same in clinic, and the oral dose of folic acid and the time of taking folic acid are often evaluated according to the level of genetic testing of folic acid metabolism, and if the gene metabolism level is poor, the folic acid may be required to be taken during the whole pregnancy. Folic acid is a vitamin that can continue to be taken orally during the middle and late stages of pregnancy. In addition to preventing fetal malformations, folic acid has other effects, such as preventing and treating anemia in pregnancy, preventing gestational hypertension and gestational diabetes.