An excess of sex chromosomes is not very common and is usually abnormal. Normally, fetal sex chromosomes are diploid, XY in males and XX in females, and an excess of sex chromosomes suggests that the number of sex chromosomes may be triploid or polyploid, which is usually detected during prenatal chromosome screening, and amniocentesis or other tests are usually required to confirm the diagnosis and to find out the exact type of sex chromosome abnormality. Sex chromosome polyploidy may adversely affect the fertility of the fetus, and the fetus may also have abnormal height, mental development, and, less commonly, development of secondary sexual characteristics. If sex chromosome hyperintensities are detected during the examination, it is recommended to consult a doctor in time, and under the doctor’s guidance, complete the relevant examinations to clarify the type and provide appropriate treatment.