If the Down’s syndrome test comes back with a high risk, the next step must be a non-invasive DNA test or an amniocentesis test. This is because a high risk Down’s syndrome may be a chromosomal abnormality in the fetus, but this cannot be determined by Down’s syndrome. The next step can be non-invasive DNA, but if the non-invasive DNA test is abnormal, or need to do amniocentesis, because amniocentesis is the most accurate, non-invasive DNA test still has a certain degree of error, the final diagnosis is to determine whether to terminate the pregnancy through amniocentesis. If the Down’s syndrome test is high-risk and the non-invasive DNA test is low-risk, you can make an informed choice about whether or not to have an amniocentesis.