The results of Down’s syndrome screening are all three low risk, which is a normal screening result, indicating that the risk of the fetus having Down’s syndrome is relatively low. During pregnancy, if the pregnant woman is infected with special pathogenic microorganisms, takes special medications or is exposed to special radioactive damage, inhales a lot of second-hand smoke, or if both spouses have chromosomal abnormalities or abnormalities in the process of sperm-egg union and fertilized egg development and differentiation, it can lead to the baby having Down syndrome. The older the pregnant woman is, the higher the risk of the fetus developing Down’s syndrome after pregnancy. Children with Down syndrome not only have significant physical and facial deformities, but also have severe mental retardation, serious internal organ malformations, and poor survival and quality of life after birth. In order to prevent the birth of children with Down’s syndrome and to improve the rate of eugenics, Down’s syndrome screening should be done promptly during pregnancy. If there are high-risk factors, further diagnosis such as non-invasive DNA testing or more accurate amniocentesis is recommended.