Down’s syndrome screening is a very important test in early pregnancy, the probability of high risk of Down’s syndrome screening is not so high, if you do 10 Down’s syndrome screening, 9 of them are high risk factors, most of them are seen in senior pregnant women, that is, pregnant women older than 35 years old. 35 years old or older pregnant women belong to the high incidence of trisomy 21, so as long as the pregnant women over 35 years old go for the test, 10 of them do The screening test for Down’s syndrome is a high-risk test. Further testing is needed for high risk of Down’s syndrome because trisomy 21 has an impact on the baby’s intelligence, growth and development. For high-risk pregnancies that require prenatal diagnosis, it is important to go to your local eugenics genetics department for further prenatal counseling and prenatal diagnosis in a timely manner.