Men who have had children who have not been stimulated by radiation, harmful chemicals and other undesirable factors do not have abnormal chromosomes, but prolonged exposure to toxic and harmful environments may result in chromosomal abnormalities in the sperm. Chromosomes are a matter of one’s own genes and generally do not change without special circumstances. Therefore, if a man has already had healthy children and has not been stimulated by radiation, harmful chemicals and other adverse factors, the chromosomes will not be abnormal. However, if after having a child, he is exposed to toxic and harmful environment for a long time, such as frequent exposure to ionizing radiation and toxic chemicals, it may cause genetic mutation and lead to chromosome abnormality. Therefore, if you want to prepare for pregnancy again, it is recommended to go to the hospital for examination and consultation to rule out hereditary chromosomal diseases, so as not to cause fetal deformities, miscarriages and other serious harm.