Amniocentesis refers to amniocentesis, and trisomy 21 refers to pediatric Down syndrome. Generally, there is a possibility of misdiagnosis in the diagnosis of pediatric Down syndrome by amniocentesis, but the chance is small, and it can be combined with other tests to make a comprehensive judgment. Amniocentesis is an important prenatal test. Pediatric Down syndrome is a chromosomal disorder caused by an abnormality of chromosome 21. In general, there is a possibility of misdiagnosis when amniocentesis is performed to confirm the diagnosis of pediatric Down syndrome, however, since the accuracy rate of amniocentesis is about 99.9%, the chance of misdiagnosis is extremely small. Amniocentesis is a definitive clinical diagnosis of pediatric Down syndrome. If there is any disagreement with the results of the test, the test can be repeated at intervals, and it can also be combined with ultrasound to measure the thickness of the fetal nuchal translucency and serum marker screening to make a comprehensive judgment. Women are advised to strengthen their daily life management during pregnancy and go to the hospital for pregnancy tests on time. If the results are abnormal, you should cooperate with your doctor for active treatment.