Infertility affects approximately 15％ of couples who have regular intercourse with male partners for over 12-month periods,without using any contraceptives.Among these infertile couples,the male factor accounts approximately 40％-50％.A significant proportion of male infertility is due to idiopathic azoospermia,severe oligozoospermia,and teratozoospermia.While some severe male infertility is associated with possible genetic alterations in germ cell lines or spermatogenesis,the cause of severe male infertility is still largely unknown.