Down syndrome critical risk is usually not a big problem, but it is not absolute, it is recommended to do further non-invasive DNA test to determine. The cut-off value for Down syndrome is 1:270, a test value of less than 1:1000 is a low risk, a test value between 1:270 and 1:1000 is a critical risk value, a test value of more than 1:270 is a high risk, a low risk indicates that the probability of the fetus having Down syndrome is small, and a critical risk requires further noninvasive DNA testing. Down syndrome critical risk is generally not a big problem, but does not exclude the non-invasive DNA test further results for high-risk cases, non-invasive DNA test results have abnormalities, to further amniocentesis to determine, according to the results of the prudent consideration of whether to continue the pregnancy. If you are pregnant and have an abnormality, you should go for further amniocentesis to determine if the pregnancy should continue.