Amniotic fluid identification generally refers to genetic-related examination by extracting fetal DNA fragments from the amniotic fluid after doing a puncture of the maternal uterine cavity and extracting part of the amniotic fluid.1. Confirmation of chromosomal abnormalities, such as trisomy 21, trisomy 18 and trisomy 13, are all chromosomal abnormalities congenital disorders. The child’s mental development and physical development are severely deficient and require termination of pregnancy after diagnosis during gestation. Various screening methods, such as mid-term Down’s syndrome screening, early NT test, 4D ultrasound, etc., can only be used as screening methods. If there is any abnormality, the diagnosis needs to be further confirmed by amniotic fluid DNA test.2. Paternity test, when the paternity between the fetus and the father needs to be identified due to special factors, DNA test can also be performed by amniocentesis.