The chromosome report card mainly looks at the morphology and number of chromosomes as well as whether there are structural abnormalities. Normal females are 46,xx and males are 46,xy, and their reports need to be interpreted by a professional genetic counseling clinic. The human body has a total of 23 pairs of chromosomes, or 46, of which 22 pairs are autosomes and 1 pair is a sex chromosome. The sex chromosomes of females have the same morphology, all of them are x chromosomes, while males have different morphologies, with one x and one y chromosome. Abnormalities of the sex chromosomes can lead to infertility, etc. In addition, if the number of chromosomes is abnormal, it is common to see 21-trisomy syndrome and 18-trisomy syndrome. Chromosomal abnormalities can usually occur in early pregnancy spontaneous abortion, a few can continue to develop and mature in the uterus, at this time, need to carry out Down screening, non-invasive DNA, amniocentesis and other tests to determine whether the fetus has abnormalities. Abnormalities in the number or structure of chromosomes may lead to symptoms such as mental retardation, poor physical development, and structural abnormalities in the fetus. Therefore, chromosome examination is of great significance to eugenics, and it is recommended that the examination be done on a regular basis under the guidance of a physician.