Folic acid is not directly related to the NT test. Folic acid can promote red blood cell maturation and hemoglobin synthesis during fetal growth and development, prevent neural tube malformation and hyperhomocysteinemia, and it is generally recommended to start taking it in the first trimester of pregnancy until about 12 weeks of gestation, and the dosage of folic acid can be increased or decreased according to the test results and the doctor’s recommendation. NT is also known as posterior nuchal translucency scan, in which the thickest part of the fetal nuchal translucency is measured by ultrasound to assess whether the fetus has Down syndrome. the higher the NT value, the higher the chance that the fetus has Down syndrome. Good health of both husband and wife can reduce the incidence of Down’s syndrome children. After pregnancy, pregnant women should have timely medical checkups and keep an eye on the growth and development of the fetus. After the third trimester of pregnancy, the physical development of the fetus is basically formed, and taking folic acid tablets has less significance in preventing fetal developmental abnormalities. However, proper supplementation of folic acid can help prevent many pregnancy complications such as anemia, hypertension and diabetes during pregnancy. In addition, the dosage of folic acid needs to be adjusted under the guidance of a doctor so as not to affect the mother and the fetus.