ABSTRACT
Undescended testis is a common abnormality, affecting 3-5 percent of male infants at birth. In preterm infants, the incidence may be as high as 20 percent or more. A significant number of testes not in the scrotum at birth descend in the first 12 weeks after birth, so that by 3 months of age the incidence of congenital undescended testes is approximately 1-2 percent. Some of those testes that descend late into the scrotum may re-ascend later in childhood, producing an acquired variant of undescended testes known as ascending testes.
