Q&A: What are retractile and undescended testis?

A retractile testis is different than an undescended one, and the two must always be distinguished, since the differences are crucial.

An undescended testis is "stuck" up in the groin or abdomen, and never makes it into the scrotum at all. Four percent of male infants are born this way. If an undescended testis hasn't come down into the scrotum on its own by 6 to 12 months, it is very unlikely to after that, and must be pulled down surgically to avoid posible infertility or cancerous changes.

Retractile testis are usually down in the scrotum, but quickly slide back up into the groin when touched because of a brisk reflex known as the cremasteric reflex. The recommendation in this situation is that they be examined every 6 to 12 months to be sure they can still be found in the scrotum (ie: that they aren't becoming undescended.) This means checking at his usual well child check-ups, which should be done routinely anyway. Having a retractile testis does not put your boy at increased risk for either infertility or testicular cancer.