The chromosome examination program for couples includes the karyotype, number of chromosomes, and whether there are any chromosome mutations in both sexes. 1. Karyotype of chromosomes: Normal male chromosome karyotype is 46, XY, female chromosome karyotype is 46, XX; this item is mainly to assess whether the gender and chromosome karyotype are consistent. 2. Number of chromosomes: The number of chromosomes in a normal human body cell is 46, and has a certain shape and structure. This test is mainly to assess whether the number, shape and structure of chromosomes are abnormal. 3. Chromosome mutation: the probability of chromosome mutation is around 10-15%, but not all chromosome mutations have clinical significance. It is necessary to assess on a case-by-case basis whether the chromosomal variant is harmful to the individual’s health and whether it will affect the birth of offspring. If a couple needs to undergo a chromosome test, it is recommended to go to a regular hospital or a chromosome testing facility. If the results are abnormal, a prenatal genetic counseling clinic is needed to evaluate the condition and choose a suitable method of conception.