Low risk screening for Down’s syndrome means that the fetus has a low probability of having Down’s syndrome and generally does not require special treatment and can continue the pregnancy. Down’s syndrome screening is a blood test that screens the fetus for the presence of Down’s syndrome, or trisomy 21, and determines the risk of trisomy 18 and neural tube defects. However, Down’s syndrome screening is only a risk assessment and the result is a risk value that can only be used for screening purposes and is subject to false positives and false negatives. Therefore, a low risk test does not guarantee that the fetus will be 100% free of Down syndrome, but only indicates a relatively low risk of the disease. If the risk of Down’s syndrome is low, the pregnant woman should still have regular maternity checkups during pregnancy and systematic ultrasound screening in the middle of pregnancy to rule out any abnormalities in the fetus. If the results of Down’s syndrome screening show a critical risk, that is, a gray area, further non-invasive DNA testing is needed to clarify the diagnosis; if the risk is high, amniocentesis is needed to clarify the diagnosis.