The Down’s syndrome screening risk values are low risk, high risk and critical risk, with a test result of less than 1:1000 being considered low risk. Down’s syndrome screening can indirectly determine the risk of Down’s syndrome in a fetus, mainly through serologic methods. The Down’s syndrome screening risk values are low risk, high risk and critical risk. A test result less than 1:1000 is considered low risk, between 1:1000 and 1:275 is considered critical risk, and if it is higher than 1:275, it is considered high risk. In general, low risk often indicates that the chance of the fetus developing a congenital anomaly is low, but it cannot be completely ruled out. High risk and critical risk are considered abnormal and require further prenatal diagnosis or non-invasive DNA testing as prescribed by the doctor. Currently, there is no effective treatment for Down’s syndrome, and screening during pregnancy is the only way to prevent the birth of Down’s syndrome babies. Therefore, pregnant women should undergo Down’s syndrome screening in accordance with their doctor’s instructions, and the results should be analyzed by a professional doctor.