Overview. Undescended testicle (cryptorchidism) is the most common genital abnormality in males. Approximately 4 percent of boys are born with the condition, and among boys born prematurely the proportion is much higher – roughly 30 percent. For most of these infants, the testicles will descend on their own within the first year of life, but when they don’t, surgery is often needed to prevent future complications.
Causes. In the normal development of a male fetus, the testicles form inside the abdomen and then migrate down into the scrotum just before birth. When one or both testicles aren’t found to be in the proper place at birth – usually upon the initial examination – it can mean one of several things. In some cases, a testicle never formed; in others, it may have atrophied or shriveled from a twisting or blockage of the testicular blood vessels. More often, the testicle has improperly descended and remains either within the abdomen or just above the scrotum. (Testicles can also be “retractile” – gliding back and forth between the scrotum and the groin – a normal condition that will resolve itself at puberty. Often these testicles can be found and brought down during examination, but not always.)
Management. For half to three -fourths of boys born with the condition, the testicles descend into the scrotum on their own during the first year of life. When this hasn’t occurred by the age of 1, an intervention to bring them down helps to reduce the risk of damage to the testicle and to prevent later problems related to sperm production and fertility. The scrotum helps to keep the testicles cool, and the higher temperature inside the body can impair normal production of sperm. The undescended testicle may also be more susceptible to injury or torsion (twisting), and can lead to cosmetic concerns or embarrassment. In addition, being born with an undescended testicle increases the risk of later developing testicular cancer. Having the testicle in the scrotum facilitates the regular physical examination that is necessary to monitor for any potential signs of malignancy.
Treatment. Treatment usually involves surgical repositioning of the testicle into the scrotum via an orchiopexy – a small cut in the groin to allow the testicle to be brought down and “pexed” into its place in the scrotum. In some cases, injections of the hormone hCG are given in an effort to induce descent, though success rates are low.