A negative value of non-invasive trisomy 21 test is normal, which generally indicates that the fetus is less likely to have trisomy 21 and is safer.
Non-invasive DNA test is a very important test, through this test can understand the growth and development of the fetus, to determine whether there is a fetal chromosomal abnormality and other symptoms, the value of about -3 and 3 between, as long as within this range, is generally normal, do not need to be overly worried, if higher than 3 means that there is a high risk.
In the course of pregnancy, it is necessary to see a doctor regularly for various examinations, such as Down’s test, 4D ultrasound, and if there is a high risk of Down’s test, it is recommended to carry out non-invasive DNA test or amniocentesis in a timely manner.