Oral folic acid should be started immediately after the discovery of an unwanted pregnancy, and regular obstetric checkups and complete ultrasound examinations should be performed during pregnancy to rule out the possibility of neural tube malformations in the fetus. It is generally recommended to start taking oral folic acid in the first trimester to prevent neural tube malformations and cleft lip and palate. If you find out that you have an unwanted pregnancy and you want to have a baby, it is recommended that you start taking oral folic acid tablets immediately. The chance of fetal neural tube malformation is 3 per 1,000, even if there is no oral folic acid before pregnancy, the fetus does not necessarily have malformation, food also contains folic acid, regular ultrasound during pregnancy to rule out fetal neural tube malformation can be. For pregnant women who have given birth to a fetus with neural tube malformation in the past, it is recommended that they take oral folic acid under the guidance of a doctor.