Amniocentesis is mainly used to rule out the presence of fetal abnormalities, chromosomal abnormalities and hereditary metabolic diseases. It is a confirmatory test to detect chromosomal abnormalities and usually takes 10-15 working days for the results to be taken out. After amniocentesis, the XY chromosome, chromosome 21, chromosome 13 and chromosome 18 are checked for abnormalities by rapid fluorescence. The results of this part of the test usually come out in 3-5 working days after amniocentesis, while the final determination of chromosome abnormalities is based on the number of chromosomes and the presence of translocations or inversions. There are 46 human chromosomes, so the project is extensive and takes a long time, 10-15 working days. Amniocentesis is performed at 16-24 weeks of gestation, the best time is 18-22 weeks of gestation, and there are risks associated with amniocentesis, so it is recommended to go to the obstetrics department of a regular large hospital for the puncture. After the puncture, care should be taken to avoid infection at the puncture site and avoid overexertion.