The screening test is a method to determine the risk of fetal disease by measuring certain specific markers in the serum of pregnant women between 14 and 21 weeks of pregnancy. In general, any one of these tests is serious, but the screening is only a risk indication and further tests are needed to make a clear diagnosis. 1. 21-trisomy high risk: it may be 21-trisomy syndrome, the fetus may have abnormal development of other organs such as face and limbs, and also abnormal development of intelligence; 2. 18-trisomy high risk: it may be 18-trisomy The fetus may have abnormal cranial development, congenital heart disease, feeding difficulties, low response, etc.; 3. High risk of neural tube defects: It indicates that the fetus is more likely to have neural tube disease, and the central neural tube cannot develop normally and has defects. If the Down screening indicates high risk, it is recommended that the pregnant woman should not be overly nervous, because the Down screening is not the final diagnosis, and the accuracy of the test results can be affected by overexertion and emotional distress of the pregnant woman. It is recommended that pregnant women continue to undergo more accurate non-invasive DNA screening, or amniotic fluid or umbilical cord puncture, which can directly observe the fetal cells for a definitive diagnosis.