Undescended testicles

Undescended testicles is a condition where one or both of a boy’s testicles (also known as testes) have not moved down into the scrotum where they should be located.

About one in every 20 boys in Australia are born with undescended testicles.

Undescended testicles are usually discovered during a medical examination of the newborn baby – either shortly after the baby has been born or at a follow-up doctor’s appointment in the weeks after birth.

The testicles are the male sex glands, and produce sperm and hormones needed for reproduction. During development, the testicles form inside the baby's abdomen and move down a tiny passage in the groin, called the inguinal canal, into their usual location in the scrotum. The scrotum is a small sac of skin which holds the testicles. This process normally happens before the baby is born. When it doesn't, the baby is said to have undescended testicles (the medical term for this is cryptorchidism). In most cases the testicles are stuck in the inguinal canal but sometimes they are stuck in the abdomen. In many cases the delay is temporary, but if the testicles haven’t moved into the scrotum by the time a boy is 6 months of age, treatment will probably be needed.

Symptoms of undescended testicles

Undescended testicles are not painful and do not usually cause any symptoms. Most boys with the condition are otherwise healthy. The main sign is not seeing or feeling one or both testicles in the scrotum. In some cases, the undescended testicle may be felt in the abdomen.

Causes

It's not known exactly why some boys are born with undescended testicles, but experts think that several factors may play a role, including genetics, hormonal problems and changes in nerve activity during development.

Some risk factors may increase the chances of a boy having the condition, including:

  • Being born prematurely (before the 37th week of pregnancy)
  • Low birth weight
  • Family history of undescended testicles.

Sometimes boys with other medical conditions have undescended testicles. For example, it is more common in babies born with spina bifida, Down syndrome and Klinefelter’s syndrome.

How are undescended testicles diagnosed?

The condition is usually picked up during an examination of the scrotum in a newborn boy. Because it’s quite common, doctors routinely check to see if both testicles are in the scrotum when they examine all newborn baby boys. If they can’t be felt inside the scrotum, the doctor will see if they can be felt near the scrotum or if they can’t be felt at all.

No further tests are needed to locate the testicles if they can be felt by the doctor. However, if they can’t be found, further tests may be required to see if they are inside the abdomen. This may include doing keyhole surgery (called a laparoscopy) to look inside the abdomen.

Can the testicles still descend after birth?

Yes. In many cases, the testicles will descend into the scrotum in the months after birth. However, this is less likely the older your baby becomes and treatment may be needed.

Complications associated with undescended testicles

If the testicles don’t descend into the scrotum they do not develop properly. This can cause a range of health problems later in life, including:

  • Fertility problems: Men who have had undescended testicles often have a lower sperm count and poor sperm quality, leading to problems with fertility. This is probably due to the fact that when the testicles are in the scrotum they are relatively ‘external’ and are at a lower temperature than when inside the abdomen. Exposing the testicles to higher temperatures can affect sperm production.
  • Testicular cancer: This type of cancer is more common in men who have had undescended testicles. This risk appears to be greater when both testicles have been affected, and when the testicles are stuck in the abdomen compared to lower down in the inguinal canal.
  • Testicular torsion: Sometimes the cord that carries semen, blood vessels and nerves becomes twisted, cutting off blood to the testicle. This is a serious condition that requires prompt treatment in order to save the testicle from permanent damage. It is more likely to occur in males who have undescended testicles.

What are retractile testicles?

Retractile testicles are not the same as undescended testicles.

In some boys the testicles are said to be ‘retractile’, which means that, although they are fully descended, tiny muscle contractions cause them to temporarily move up and out of from the scrotum. This often happens in cold weather and can also happen when a boy feels scared or excited. Retractile testicles usually settle down as a boy gets older, but may need to be monitored to make sure the testicles end up in the scrotum.

Acquired undescended testicles

Sometimes the testicles are present in the scrotum at birth, but ‘disappear’ later on. This is called ‘acquired’ undescended testicles or acquired cryptorchidism, and can happen up to the age of about 10 years. It may be caused by an abnormally short spermatic cord. As a boy grows the cord may not grow at the same pace as the rest of the body, causing the testicle to be pulled back up into the groin.

Treatment

If the testicles haven’t descended by 6 months of age they are probably not going to, and treatment is usually required. Undescended testicles are usually treated with surgery.

  • Surgery: This type of surgery is called orchidopexy. It involves making a small incision in the groin, finding the testicles and moving them down into the scrotum. This may be done in boys as young as six months of age and is the most common treatment for undescended testicles in Australia.

Should boys be told that they have had undescended testicles?

Yes. It’s very important to let boys know that they have had this condition because they have a greater risk of health problems when they are older, such as fertility problems and testicular cancer.

Prevention

At this stage, medical experts don’t know how to prevent undescended testicles. That’s why it’s important to check babies to see if the testicles are where they should be. If you have baby boy, it is wise to check that you can feel both testicles in his scrotum. This is easily done when he is sitting in a warm bath.

Last Reviewed: 27 May 2016
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References

1. Andrology Australia. Undescended testes. Fact sheet (reviewed February 2015). https://www.andrologyaustralia.org/wp-content/uploads/Factsheet_UndescendedTestes.pdf (Accessed May 2016).
2. NHS Choices. Undescended testicles (reviewed September 2015). http://www.nhs.uk/Conditions/undescendedtesticles/Pages/Introduction.aspx (Accessed May 2016).
3. Royal Children’s Hospital, Melbourne. Undescended testes. Updated Oct 2010. http://www.rch.org.au/kidsinfo/fact_sheets/Undescended_testes/ (accessed May 2016).
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