Non-invasive DNA (deoxyribonucleic acid) testing, also known as non-invasive prenatal DNA testing, is a testing technique that tests the genes of the fetus by detecting fetal free DNA in the maternal plasma, so as to clarify whether the fetus suffers from certain congenital diseases. Because fetal chromosomal abnormality will cause trace changes in the DNA content of the mother’s body, the non-invasive DNA prenatal testing technology only needs to take the pregnant woman’s venous blood, and then sequencing and analyzing the free DNA fragments in the mother’s peripheral plasma (including fetal free DNA), from which the genetic information of the fetus can be obtained. Nowadays, hospitals mainly use non-invasive DNA testing to clarify whether the fetus has Down’s syndrome, Edward’s syndrome, Patau’s syndrome and other diseases. Non-invasive DNA testing is very helpful in achieving eugenics. The results of non-invasive DNA are more accurate, but the most accurate and comprehensive prenatal test for the diagnosis of congenital disorders is amniocentesis.