The following excerpt is from an article that originally appeared on Science Based Medicine
A missing testicle is a fairly common finding when examining newborn infants, particularly when they are born prematurely. We commonly refer to this finding as cryptorchidism, although by strict definition that term specifically applies to testes that haven’t fully completed their epic journey into the scrotum by 4 months of age. Cryptorchidism, which is also diagnosed initially when one or both testes is absent, is the most common congenital abnormal finding related to the male genitourinary tract.
Most cases of cryptorchidism involve undescended but healthy testes. As mentioned above, sometimes one or both of the testicles are missing, or shriveled and useless, because of vascular compromise that occurred at some point prior to delivery. Testicles that have descended, but are prone to retracting out of the scrotum, are called retractile testes and while the phenomenon usually resolves over time they are at increased risk of evolving into a true undescendedpost was originally published on this site