Undescended testicle(s) (also known as “cryptorchidism”) is when one or more of a male baby’s testicles has not yet moved into its proper position in the scrotum before birth. Testicles typically descend into the scrotum between weeks 32 to 36 into pregnancy. Premature babies are more likely to be affected by cryptorchidism. The undescended testicle should return to the scrotum in the first months of life; if not, surgery may be required.

What are undescended testicles?

Undescended testicles in a condition in which a person’s testes have not moved down into their proper place in the scrotum, the bag of skin below the penis. Usually, testicles will move into the scrotum before birth. In some cases, babies may be born with one or both testicles undescended. The reason why some babies are born with undescended testicles is unknown, but studies have shown that this occurs most often in babies that are born prematurely. 

If a baby is born with undescended testicles, they should descend by the time they reach 6 months of age. If testicles have not descended by this time, it’s important to discuss treatment options with a doctor. The testicles create and store sperm. They can become damaged or underdeveloped if they do not properly descend into the scrotum, potentially impacting fertility later in life or leading to medical problems.

Undescended testicles and male fertility

The testicles need to be below regular body temperature to produce sperm, which is why they descend into the scrotum. Heat is not good for sperm production and can cause damage and distress. Sperm production happens optimally around a temperature of 93ºF, which is 5.4ºF below normal body temperature of 98.6ºF.

Since undescended testicles are located higher up in the body in the “inguinal canal,” they experience higher-than-optimal temperatures. Over time, this can harm the testicle’s development and ability to produce sperm. This is why it’s important to be vigilant about treatment — the sooner undescended testicles are treated, the less likely it will impact fertility in the future. 

Studies also show that people who had two undescended testicles at birth are more likely to experience reduced fertility than people who were born with just one undescended testicle. 

Treatment for undescended testicles

If a baby’s testicles have not descended by the time they are 6 months old, it’s time to discuss treatment options with their pediatrician. The most common course of treatment is a surgical procedure called orchiopexy. This procedure involves a small cut made in the groin so the surgeon can reposition the testicles down in the scrotum.