You can take folic acid in the first month of pregnancy, and take it until the end of the fourth month after pregnancy, the folic acid taken by pregnant women is more appropriate 0.4mg per tablet. Folic acid is a water-soluble B vitamin, vitamin B9. folic acid plays an important role in the secretion and growth of cells and the synthesis of nucleic acids, amino acids and proteins. the lack of folic acid in the human body can lead to abnormalities in the red blood cells, an increase in the number of immature cells, anemia, and a decrease in the white blood cells. Folic acid is an indispensable nutrient for the growth and development of the fetus. Lack of folic acid in pregnant women can lead to low birth weight, cleft lip and palate, and heart defects. If you are deficient in folic acid during the first 3 months of pregnancy, it can cause congenital neural tube development defects in the fetus and lead to malformations, so pregnant women should take folic acid supplements during pregnancy.