If you have not been taking folic acid in the third trimester of pregnancy, it usually does not have much effect, or you can go to the hospital for a checkup to determine whether the fetus has a neural tube abnormality. Folic acid supplementation in the right amount during pregnancy preparation and pregnancy can prevent neural tube malformations in the fetus during development. If you have not been taking folic acid during the third trimester of pregnancy, there is no need to be overly nervous. Pregnant women can go to the hospital for tests to determine whether the fetus has neural tube malformation. During pregnancy, she should have regular maternity checkups, maintain a good lifestyle, avoid contact with toxic and harmful substances, and should not use medication privately. Pregnant women are advised to go to the hospital in time if they feel unwell.