The need to continue taking folic acid after the third month of pregnancy depends mainly on the results of the folic acid genetic screening. Under normal circumstances if no abnormality is found in the folic acid genetic screening, the medication can be stopped after taking it until the 3rd month of pregnancy. Pregnant women at risk of folic acid metabolism should control the duration of taking folic acid or even increase the amount of folic acid under the guidance of their doctor according to the screening results. Also if there is a history of bad pregnancy, application of anti-epileptic drugs during pregnancy, etc., it is necessary to continue taking folic acid.1. Risk of folic acid metabolism: If some women have mutations in folic acid metabolism genes, it can lead to some reduction in folic acid absorption, which can cause an increase in homocysteine and cause pregnancy complications such as hypertensive disorders in pregnancy, preterm delivery, fetal growth restriction, placental abruption, etc. In this case, it is recommended to continue taking oral folic acid after 3 months, and homocysteine levels need to be rechecked regularly, and if they have returned to normal values, folic acid supplementation can be stopped; 2. Adverse pregnancy history: if a pregnant woman has delivered a fetus with hydrocephalus or spina bifida during her previous pregnancy, she also needs to take high doses of oral folic acid and continue supplementation after 3 months; 3. Application of anti-epileptic drugs: if a pregnant woman, during pregnancy, has taken oral anti-epileptic drugs for If a pregnant woman takes anti-epileptic drugs orally for her own reasons, folic acid also needs to continue to be taken to prevent the drugs from affecting the absorption of folic acid up to the required dose. It is recommended to stop taking folic acid supplements if pregnant women find an increase in transaminases in their liver function. In addition, individual pregnant women may have more obvious reactions such as nausea and vomiting after taking folic acid orally, so they can reduce the dosage or stop taking it appropriately. After the third month of pregnancy, calcium and iron supplements are needed, usually starting from the fourth month of routine calcium supplementation and iron supplementation according to anemia. When supplementing these medications, it is important to space them out and not take them at the same time.