You don’t need to do Down’s screening if you’ve already done non-invasive DNA testing during pregnancy. Both are to check whether the fetus has congenital diseases caused by chromosomal abnormalities, Down’s syndrome screening is only a preliminary screening for chromosomal diseases, the accuracy is not high, only about 70%. Non-invasive DNA testing has a high accuracy rate of over 95%, which is significantly higher than Down’s screening. Generally, when there is a problem with the fetus in the initial Down’s syndrome screening, non-invasive DNA is the only option for further testing, and since non-invasive testing has already been done, there is no need to do Down’s syndrome screening again. As long as the non-invasive DNA test is clean, the pregnancy can continue.