In everyday life, men have both testicles, which allows them to have normal reproductive functions. However, some men are born with only one testicle, or both testicles are missing, which is called cryptorchidism. This is called cryptorchidism, because one or both testicles are hidden inside the male body and do not descend into the scrotum, so only one or both are missing. Can cryptorchidism cause male infertility? The testicles descend from the retroperitoneum into the scrotum during fetal life. If they stay in any abnormal area during descent, such as near the lumbar region, abdomen, inguinal canal inner ring, inguinal canal or outer ring, it is called cryptorchidism. Does cryptorchidism cause male infertility? Medical studies have proven that patients with cryptorchidism have normal levels of testosterone in their blood. Therefore, it is reasonable to say that cryptorchidism will not cause sexual problems in adulthood. However, it cannot be denied that because the body of the affected child is different from that of a normal person, the normal development of cryptorchidism is affected due to the high temperature in the abdominal cavity. When puberty comes, the amount of androgen (testosterone) produced by the stunted testicles is very little, and the secondary male sexual characteristics are not obvious and the sexual desire requirement is also little. Cryptorchidism can have an impact on the psychological state of the affected child, especially the psychosexual development. If a boy with cryptorchidism is mentally burdened by frequent examination of his sexual organs, or if his testicles do not descend even after hormone treatment, it may lead to psychosexual disorders. The absence of testicles in one or both scrotums will inevitably affect the normal psychological development of the child, resulting in low self-esteem, shyness, self-containment and even abnormal sexual psychology, which in turn will lead to sexual problems in adulthood, such as impotence and psychosexual diseases. Doctors must tell the parents of the affected children about the nature of cryptorchidism and its impact on sexual function and psychosexuality in adulthood, so that they can have a correct understanding. Can men with cryptorchidism still have children? If there is cryptorchidism on both sides, it may cause infertility due to azoospermia, and the incidence is 50-100%. Some people think that as long as one side of the testicle has dropped, they can have children, so they don’t need to have surgery to remove it. In fact, this idea is wrong. Unilateral cryptorchidism, which can spread to the opposite testicle, and the presence of the testicle, will have the possibility of atrophy, and even the smaller atrophied testicle should be removed because it can produce an antibody that can damage the opposite testicle. The incidence of infertility is 30-60%. Moreover, the chance of tumor in cryptorchidism is 20-50 times higher than that of normal people. About 8% of patients with cryptorchidism will develop cancer. The high incidence age is usually between 25-35 years old. It has been pointed out that a repositioned testicle after the age of 10 does not help restore fertility and does not reduce the possibility of malignancy. It can only be removed to prevent malignancy. Sperm, the root of male fertility, is produced and developed in the testes and has a direct relationship with male fertility, while the scrotum is the most suitable place for its normal growth and development. If the testicles fail to reach the scrotum for various reasons and stay in other parts of the body, and the temperature and biochemical environment of these parts are not conducive to the growth and development of the testicles, the testicles there will be underdeveloped or not developed at all, and then the testicles will not be able to perform the function of sperm production and fertility, thus leading to male infertility. This can lead to male infertility. Can IVF treat male infertility caused by cryptorchidism? Since there is no way to prevent the occurrence of cryptorchidism, it must be taken seriously in males. Treatment during early childhood can restore fertility, but treatment around puberty can restore sexual function, but it is infertile. Moreover, men with cryptorchidism will gradually lose their fertility as they get older. Men with cryptorchidism should plan for fertility as early as possible and check whether there is still sperm production in their bodies in advance. If there is sperm production, then IVF can be used to conceive; if there is no sperm production, then, as in the case of idiopathic azoospermia, the only option is to donate sperm for conception or to adopt a child.