Taking all advanced maternal age as the base, the pass rate of amniocentesis is higher, and there is no specific probability for the time being. The pass rate of amniocentesis is higher when all the tests are normal during the pregnancy checkup. The pass rate of amniocentesis is lower when all the pregnant women with poor maternal history, high risk of Down’s syndrome, abnormal NT test results, etc. are taken as the base. It is better to do amniocentesis at 14-20 weeks of pregnancy, when the fetus is basically formed and the amount of amniotic fluid in the uterus is sufficient, so that the trauma to the fetus can be reduced when doing amniocentesis. The accuracy of amniocentesis is also high. Normal test results indicate that the fetus is developing well in the uterus and can be conceived normally, while abnormal test results should be considered cautiously whether to continue the pregnancy.