The accuracy of dna generally refers to the accuracy of noninvasive DNA testing. Its accuracy rate is generally above 96%. Non-invasive DNA testing is used to analyze and determine whether a fetus has one of the three major chromosomal disorders by drawing venous blood from the mother and sequencing the free fetal DNA in the mother’s plasma using DNA sequencing technology. Its accuracy is usually not ensured to be 100%, but can reach about 96% or above. The main reasons why the non-invasive DNA test cannot reach 100% may be due to the testing time is too early, or the pregnant woman is overweight, as well as the existence of pregnancy diseases, etc., which will cause the concentration of free fetal DNA in plasma to decrease or increase, resulting in the inability to accurately isolate the impact on the accuracy. However, the results of non-invasive DNA testing are usually fine. If there is any doubt after the test, further amniocentesis can be performed under the supervision of a doctor to make sure.