Testicular retraction is a condition in which a testicle descends normally into the scrotum, but can be pulled up with an involuntary muscle contraction into the groin.

This condition is different from undescended testicles, which occurs when one or both of the testicles have not lowered into the scrotum permanently.

Testicular retraction is more common among young boys, affecting about 80 percent of testes in boys ages 1 to 11. It tends to resolve itself by puberty.

In about 5 percent of boys with testicular retraction, the affected testicle stays in the groin and no longer moves. At that point, the condition is called an ascending testicle or an acquired undescended testicle.

A boy with persistent testicular retraction is said to have a retractile testicle.

What this means is that a testicle often moves up out of the scrotum, but may be moved by hand outside the groin down into the scrotum. It usually remains there for a while before eventually being pulled back up into the groin.

In many cases, the testicle may drop into the scrotum on its own and remain in that position for some time. Another symptom is that the testicle may ascend from the testicle into the groin spontaneously.

Testicular retraction tends to affect only one testicle. It is also usually painless, which means your child may not notice anything until the retractile testicle can’t be seen or felt in the scrotum.

Normally, in the last few months of pregnancy, a baby boy’s testicles will descend into the scrotum. The cause of testicular retraction is an overactive cremaster muscle. This thin muscle contains a pocket in which the testicle rests. When the cremaster muscle contracts, it pulls the testicle up into groin.

This response is normal in males. Cold temperature and anxiety are two factors that trigger what is known as the cremasteric reflex, or the pulling of the testicles upward toward the groin.

However, excessive contraction can result in testicular retraction.

There is no known cause for why the cremasteric reflex is exaggerated in certain boys. However, there are some risk factors associated with a retractile testicle:

  • low birth weight or premature birth
  • family history of testicular retraction or other genital disorders
  • Down syndrome or other birth defect that affects growth and development
  • maternal alcohol or drug consumption, or smoking during pregnancy

Diagnosing testicular retraction begins with a physical examination. Your son’s doctor may see that one or both of the testicles are not descended.

If the testicle can be moved down into scrotum easily and painlessly and remain there for a time, the doctor may safely diagnose the condition as testicular retraction.

If the testicle can be moved only partially into the scrotum or there is pain with movement, the diagnosis may be undescended testicles.

The condition may be diagnosed at three or four months of age, which is the age that the testicles usually descend if they haven’t already. It may be easier to diagnose the condition by the age of 5 or 6 years.

A retractile testicle is sometimes misdiagnosed as an ascending testicle. The key difference between these two conditions is whether the testicle can be easily guided down to the scrotum.

If the testicle can be easily manipulated, or moves back down by itself, that usually means it’s a retractile testicle.

If a testicle had been in the scrotum but has risen up into the groin and cannot be easily pulled back down, the condition is known as an ascending testicle. There is usually no obvious cause of ascending testicle.

Monitoring a retractile testicle to see if it sometimes comes down into the scrotum may help determine if the testicle is retractile rather than ascending, which can require surgery to correct the problem.

In most cases, no treatment is needed for testicular retraction. The condition will go away around the time puberty begins, if not before.

Until the testicle descends permanently, this is a condition that should be monitored and evaluated by a doctor at annual checkups.

If a retractile testicle becomes an ascending testicle, then surgery may be necessary to move the testicle into the scrotum permanently. The procedure is called orchiopexy.

During the procedure, the surgeon detaches the testicle and the spermatic cord, which is attached to and protects the testicle from any surrounding tissue in the groin. The testicle is then moved into the scrotum.

Boys should monitor their testicles in the unlikely event that one ascends again.

Take note of the appearance of your son’s testicles during diaper changes and baths. If it appears that one or both testicles have not descended or have ascended after having previously been in the scrotum, make an appointment with a pediatrician.

As your son gets older and learns more about his body, talk about the scrotum and testicles. Explain that there are usually two testicles in the scrotum, but if he has only one that it is a condition that can usually be treated. It does not mean there is anything wrong with him. It simply means that one testicle is a little higher than where it should be located.

Teach your son how to check his own testicles. Tell him to gently feel around the scrotum. Doing this in a warm shower is helpful, as the scrotum will hang a little lower. Tell him if he notices any changes in his testicles to let you know.

Getting into the habit of testicular self-checks will benefit him later in life as he checks for signs of testicular cancer.

Testicular retraction may be alarming to new parents, but it is usually a harmless condition that resolves on its own.

If you’re unsure what to look for with your infant or toddler son, talk with his pediatrician. If a retractile testicle does ascend permanently, discuss the timing, risks, and benefits of surgery.

The more you learn from your child’s doctor, the better you will feel about the situation and the more easily you will be able to talk with your son about it if he is old enough.