During a woman’s pregnancy, the baby boy’s testes develop in his abdomen. As he nears birth, they descend through a tube (the inguinal canal) into the scrotum. In a small number of boys, especially those who are premature, one or both testicles fail to descend by the time of birth. In many of these boys, descent will occur during the first few months of life. In some, however, this does not happen. Most boys will have a normal retraction of the testes under certain situations, such as while sitting in cold water (i.e., the testes “disappear” temporarily up into the inguinal canal). However, in general, when the boy is warm, testes should be low in the scrotum. The cause of most cases of undescended testicles is unknown. If your child has undescended testicles, his scrotum may be small and appear underdeveloped. If only one testicle is undescended, the scrotum may look asymmetrical (full on one side, empty on the other). If the testicles sometimes are in the scrotum and at other times (i.e., when he is cold or excited) are absent, and located above the scrotum, they are said to be retractile. This condition usually self-corrects as a boy grows older.
Rarely the undescended testicle may be twisted, and in the process, its blood supply may be stopped, causing pain in the inguinal (groin) or scrotal area. If this situation is not corrected, the testicle can be damaged severely and permanently. If your son has an undescended testicle and complains of pain in the groin or scrotal area, call your pediatrician immediately. Undescended testicles should be reevaluated at each regular checkup. If they do not descend into the scrotum by one year of age, treatment should be considered.
Undescended testicles may be treated with hormone injections and/or surgery. Currently, hormonal treatment is limited to cases of a very low undescended testis or some retractile testes. Many children with true undescended testes will also have an inguinal hernia and the hernia will be repaired at the same time that the undescended testis is moved to the scrotum. If your son’s undescended testicle is allowed to remain in that position for over two years, he has a higher than average risk of being unable to father children (infertility). He also has a slightly increased risk of developing testicular tumors in adult life, particularly if the testicle is left in its abnormal position. Fortunately, with early and proper treatment, all of these complications usually can be avoided.