Amniocentesis (referred to as amniocentesis, amniocentesis) is the extraction of amniotic fluid through ultrasound-guided localization for karyotype analysis of fetal chromosomes and methemoglobin determination, as well as some genetic and enzyme testing for certain genetic disorders, as shown below. Because the amniotic fluid contains fetal shed skin cells and kidney cells from fetal urine, after the amniotic fluid is extracted, the testers will perform a series of complex processes such as centrifugation, culture, staining, and reading to finally obtain the karyotype results of the fetus, in addition to sending the amniotic fluid for methemoglobin testing. Generally speaking, amniocentesis is safe, and the rate of occurrence of various risks varies from 1/250 to 1/300, which means that problems may occur in 3 to 4 cases per 1000 punctures, usually bleeding, miscarriage, infection, leakage of amniotic fluid, injury to the fetus, and sometimes amniocentesis may occur due to uterine malformation, uterine fibroids, placenta located in the anterior wall of the uterus, too thick abdominal wall, low amniotic fluid volume, etc. Failure. There are also various reasons why amniotic fluid cells do not grow in culture or grow unsatisfactorily, and thus no conclusion can be drawn.