There is no such thing as negative or good non-invasive DNA, a normal test result is good.
Non-invasive DNA belongs to prenatal screening, non-invasive DNA is to extract the peripheral venous blood of pregnant women, peripheral venous blood contains fetal DNA sequences, extraction of fetal DNA for high-throughput sequencing, screening the fetus for chromosomal aneuploidy aberrations, the test results between -3 to 3 is normal, within this range is a good result, there is no negative number is good or bad.
Not all women need to have a non-invasive DNA test when they are pregnant. When a woman’s pregnancy is over 35 years of age and she has had a child with a chromosomal abnormality in the past, she can have a non-invasive DNA test to determine whether the fetus has an abnormality.
Non-invasive DNA test can be done from 12 to 22+6 weeks of pregnancy, and if the result of the test is abnormal, further amniocentesis should be done, and the accuracy of amniocentesis is higher than that of non-invasive DNA test.
After pregnancy, you need to do regular checkups and follow the doctor’s advice if there is any abnormality. For more information, please consult your doctor.