What does undescended testes mean? During pregnancy, the testes of the male fetus are formed in the abdominal cavity. Shortly after birth, the boy’s testicles generally descend from the abdominal cavity into the scrotum through a canal-like gap called the inguinal canal. When this process is blocked (not descending), the medical term is “cryptorchidism”. In 10% to 15% of cases of cryptorchidism, both testes do not descend. Sometimes the undescended testes can descend within the first year of life, and it is highly unlikely that the undescended testes will continue to descend after 1 year of age. There are several ways to determine if an infant has a cryptorchid testis rather than a retractile testis. A retractile testis is located in the scrotum but occasionally (or temporarily) goes up to the inguinal canal. This condition does not require treatment and usually corrects itself by puberty. Who has a higher chance of developing cryptorchidism? Premature and low birth weight male infants have a high chance of developing cryptorchidism after birth. The incidence is 17% in preterm infants weighing less than 2.27 kg and nearly 100% in those weighing less than 0.9 kg. How is it treated? In general, if the testicles do not descend in the first year of life, the child will need hormone injections or surgery. The procedure is called testicular descent, where the testicles are lowered and placed in the scrotum. The surgery itself causes mild discomfort and most children are able to move around freely soon afterwards. Why is treatment needed? Treatment is needed for several reasons: 1. The high temperature in the body relative to the scrotum inhibits the normal spermatogenesis of the undescended testicle; 2. The undescended testicle has a high risk of tumor formation; 3. The undescended testicle is more susceptible to trauma; and 4. An asymmetrical or empty scrotum can cause worry and anxiety. Should parents be concerned? Because undescended testes are often combined with inguinal hernia, we remind parents of children with cryptorchidism to pay attention to the lump in their child’s groin. Because the hiatal hernia forms in the pathway of the descending testicle, there is a risk of damage to the testicle or intestinal obstruction. Children with undescended testes may develop infertility. Although testicular tumors are rare, boys with undescended testicles have a high chance of developing testicular cancer. Parents do not have to be overly concerned, but need to be aware of this. When the child is older, simply let him know that he has had testicular descent surgery and that he needs to have his testicles checked regularly. The doctor can teach him how to perform a self-examination. If any abnormalities or lumps are found, they need to be seen.