Fetal chromosome XXY may be related to the parents. The presence of XXY chromosomes in a fetus is usually due to a genetic mutation, and the main causes are genetic factors as well as a history of exposure to related teratogenic factors. There are two types of sex chromosomes in the human body, XX and XY, which determine the sex of a person. Fetal XXY may be the result of a maternal XX chromosome that did not separate during meiosis and was passed on to the fetus. Fetal chromosomes are produced by the combination of both parents’ chromosomes. Fetal XXY chromosomes do not exclude the existence of teratogenic factors in the external environment, such as rays, taking some drugs during pregnancy. Pregnant women during pregnancy, you need to carry out regular obstetric examination, to avoid some teratogenic factors, you need to take medication under the guidance of the doctor, do not take medication to avoid the impact on the fetus.