An undescended testicle is one which is missing from the scrotum and is lodged in the groin or in the lower abdomen. This doesn’t cause any pain and doesn’t affect the way a boy passes urine (wee).
Undescended testicles can cause problems because if the testicle is in the abdomen, it may be too warm for normal development of sperm.
If the undescended testicle is not brought down in the first year or 2 of life, it may affect a boy’s ability to make sperm and father children later in life.
A person with an undescended testicle also has a greater chance of getting testicular cancer in adult life.
Types of undescended testicles
There are 2 types of undescended testicles:
- Congenital – where 1 or both testicles do not descend at birth or over the following few months. This is more common in boys who are born prematurely, or are very small when they are born.
- Acquired – in some boys a testicle gradually moves up out of the scrotum between the ages of 1 and 10. This is called an acquired or ascending testicle and should be checked as it may need treatment.
Checking for undescended testicles
Check that both testicles are in the scrotum in the few months after birth. Your doctor and child health nurse will routinely check during this time.
If it is hard to find or see the testicles in the second 6 months of life, check with a doctor or your child health nurse.
As boys grow, it is important to check every year or so to be sure the testicles can be seen or felt in the scrotum. If you cannot find one or both, check with your doctor or child health nurse.
Your child health nurse will check your child’s testes at each child health (purple book) appointment (external site) from birth to 12 months.
If the scrotum or testes become red, swollen or painful at any age it is important to see a doctor immediately.
Treatment for an undescended testicle
If a testicle does not come into the scrotum in the first 6 months, an operation called an orchidopexy is done to bring it down and fix it in place. This is usually done around 12 months of age.
If the testicle moves up out of a boy’s scrotum, a similar operation is done to fix it down.
Undescended testicles are still operated on if they occur after the age of 2 to reduce the chances of testicular cancer.
Testicles that move up and down (retractile testicles) do not need treatment, but should be monitored as they are more likely to become undescended.
Fertility of undescended testicles
Biopsies of undescended testicles (where a small sample of testicular tissue is examined) have shown that the number of sperm-forming germ cells are normal until the age of 6 months. Germ cell numbers start to reduce in number after that age.
In the second year of life over one third of undescended testicles will lose all germ cells. This means they will be unable to form sperm.
The number of germ cells present at the time of an orchidopexy is related to sperm counts later in life.
The fertility of retractile testicles (testicles that move in and out of the scrotum) is normal.
One normal testicle is sufficient for normal fertility (the ability to have children).