Folic acid is a water-soluble b-vitamin, so called because it was originally extracted from spinach leaves. Folic acid is mainly found in beans, spinach, tomatoes, carrots and other foods, it can not be produced by the body, but can only be ingested from food or as a drug supply. Folic acid has the function of anti-anemia, but also helps to improve the intelligence of the fetus. Once the lack of folic acid during pregnancy may lead to spina bifida, limb bone disease, brain cavity malformation. The level of folic acid in pregnant women is significantly lower than that of non-pregnant women. The World Health Organization recommends a daily intake of 0.4 mg of folic acid for pregnant women. 3 to 6 weeks after the start of pregnancy is the critical period for the growth and development of the embryo’s central nervous system, which is also most susceptible to the influence of teratogenic factors. As a precautionary measure, women who are planning to get pregnant should consume more folic acid-rich foods within 3 months before pregnancy and take 0.4 mg of folic acid every day until 3 months after pregnancy. In this way, the incidence of neural tube malformations can be significantly reduced. In addition, folic acid has the effect of improving the quality of sperm, so the father can also take some folic acid to improve the quality of sperm before preparing for pregnancy.