Trisomy 21, also known as Down’s syndrome, is a common genetic disorder caused by chromosomal abnormalities, and most children with trisomy 21 have mental retardation, special facial features, and other organ malformations. The birth of a baby not only places a heavy burden on the family, but also significantly reduces the quality of their survival. If the mother’s test results show a high risk of trisomy 21, the chances of having a baby with Down’s syndrome are significantly higher than other normal babies, so she needs to consult a professional obstetrician and gynecologist for a detailed assessment and further prenatal diagnosis to determine whether she needs to have a normal pregnancy or choose abortion.