Men in their 80s can theoretically have children, but individual differences have to be taken into account. The male sex organs and their functions gradually decline with age, and so does fertility, but there is no clear cut-off point for termination. The male testes are capable of producing sperm continuously, but with age, the number of sperm decreases, senescent or immature sperm may increase, sperm motility and activity rate also decrease, malformation rate increases, and overall sperm survival rate decreases. The quality of sperm has a direct impact on fertility, so routine semen examination is required as a reference for determining fertility. Men in their 80s who have basically normal sexual function and fair sperm quality are still fertile if they are able to accomplish natural conception. If the sexual function has declined or if he has suffered from other diseases that prevent natural conception, artificial insemination can be used to achieve fertility if the quality of sperm is acceptable. Those with poor sperm quality will not be able to have children.