Each of us has 23 pairs of chromosomes, of which 22 pairs of autosomes control the general traits of the human body, and the other pair of sex chromosomes control our sex organs and fertility. Abnormalities of either autosomes or sex chromosomes may affect fertility, but abnormalities of the sex chromosomes are more closely related to infertility. Research results show that 2%-20% of male infertility may be related to chromosomal abnormalities, common sex chromosome aneuploidy changes, for example: Klinefelter syndrome is due to patients with an extra X chromosome, Y chromosome more may also lead to infertility, such as 47XYY. in addition to chromosomal structural abnormalities, such as deletions, insertions, and ectopic, etc., may also lead to male infertility. It seems that chromosomal abnormalities cause a lot of trouble, so which men need to do chromosome examination? Roughly summarized as follows: semen quality serious abnormalities 1, serious oligospermia and azoospermia, which is especially sperm density is less than 5 million and azoospermia patients, it is recommended to further do the Y chromosome microdeletion examination. 2.Abnormal spermatozoa Patients with 2 or more tests have an abnormality rate higher than 96%. 3, Leukocytospermia It is best to examine the sperm chromosomes and DNA fragments. Second: Unexplained adverse maternal history Couples with 2 or more unexplained miscarriages, abortions, malformations and so on. Third: Abnormal development of the reproductive system Such as small testes in men, hypoplasia of secondary sexual characteristics and patients with hypoplastic vas deferens. Fourth: Diagnosis of the etiology of idiopathic infertility refers to any disease or abnormality related to infertility that cannot be detected by the application of existing medical technology. Fifth: Selection of Indications for Assisted Reproductive Technology Chromosomal screening can effectively reduce the risk of offspring birth. Sixth: other For people over 40 years old who still want to have children, and people with special occupations such as exposure to radiation, chemical materials, etc., chromosome-related tests are recommended.