What is an Undescended Testis?
An undescended testis, also known as cryptorchidism, is a condition where one or both of a male infant’s testicles do not descend into the scrotum before birth. Normally, during fetal development, the testicles form in the abdomen and gradually move through the groin and down into the scrotum during the last few months of pregnancy. However, in some cases, this process doesn’t complete, resulting in one or both testicles remaining in the abdomen or groin area.
Cryptorchidism is one of the most common genital abnormalities in male infants, affecting around 3-5% of full-term boys and up to 30% of premature infants. Most cases involve only one undescended testicle, but in some cases, both testicles may be affected.
Types of Undescended Testes
Palpable Undescended Testis
This means the testis can be felt in the groin but has not descended into the scrotum.
Non-Palpable Undescended Testis
The testis cannot be felt, and may either still be in the abdomen or absent.
Why Does an Undescended Testis Occur?
The exact cause of undescended testis is not always clear, though it is likely influenced by a combination of genetic, hormonal and environmental factors.
Common risk factors include:
- Premature birth
- Low birth weight
- Family history of undescended testes
Undescended testis can also occur as part of a certain conditions, syndromes or chromosomal disorders, including those involving variations in sexual characteristics (also called ambiguous genitalia or disorders of sexual differentiation).
Does an Undescended Testis Need Treatment?
Yes, in most cases. The treatment for undescended testes is an operation called orchidopexy, which moves the undescended testis into the scrotum. The testes need to be in the scrotum to function optimally. When the testes remain in the abdomen or groin, they are exposed to higher body temperatures, which can impact their function. The main reasons for treatment include the following.
Risk of Impact on Fertility:
The testicles need to be in the scrotum where it is cooler, which is important for producing healthy sperm. Boys with both undescended testicles are at a higher risk of infertility later in life.
Risk of Testicular Cancer:
There is a slightly higher risk of testicular cancer in boys with undescended testes. The risk for testicular cancer in men generally is estimated at 1 in 100,000, but this is higher if the testes are undescended. If the testes are not within the scrotum, testicular cancer may not be diagnosed until a much later stage and more severe disease.
By bringing the testicles into the scrotum, it becomes easier to monitor for any abnormal changes during self-examination as they grow older. Boys should be taught to perform self-examinations from adolescence.
Risk of Testicular Torsion:
An undescended testis has a higher risk of twisting, which cuts off its blood supply, a condition known as testicular torsion. Testicular torsion needs to be diagnosed quickly and may require urgent treatment as it can cause permanent damage to the testis.
Other Complications:
There’s also a higher risk of developing an inguinal hernia, where part of the intestine bulges into the groin area.
How is an Undescended Testis Diagnosed?
An undescended testis is typically diagnosed during a routine physical examination at birth or during early health check-ups. The clinician will feel the baby’s scrotum and groin area to check if both testicles are in place.
It’s important to note that an ultrasound is not typically recommended. It’s normal for the testicles to be able to be able move from the scrotum up into the groin, making it difficult to get an accurate result from an ultrasound.
If you are concerned, please see your family doctor. If they suspect an undescended testis, or if there are ongoing concerns, a paediatric surgeon will need to see your child.
Retractile Testis and Ascending vs. Undescended Testis
The testes are normally ‘retractile’ – this can describe the normal movement of the testes between the scrotum and groin. Testes do not sit permanently in the scrotum – they should be able to move freely up and down controlled by the cremaster muscle in the groin.
The testes will normally retract into the groin when the temperature is cold, and then relax when warm. With physical activity or even being nervous, the testes are also pulled up into the groin. This is a normal response.
Testicular retraction can occur when the testes are more persistently retracted, and do not relax into the scrotum. They may still be able to be pulled down manually during examination. This is different to undescended testes, in which the testes have not descended properly from the abdomen during development.
An ascending testis occurs when the normally descended testicle has been persistently retracted back up into the groin and doesn’t relax back down to the scrotum, and it cannot be easily pulled back down when examined. An ascending testis generally rises over time, especially as the boy grows taller. This can take years to diagnose, and often the reason for ongoing reviews of retractile testis over the first few years of life. Ascending testis may require a procedure to correct the position, for similar reasons to undescended testis.
Is an Undescended Testis Dangerous?
While not immediately dangerous, an undescended testis can lead to long-term issues if not treated. These include fertility problems, increased risk of testicular cancer and testicular torsion.
To prevent these problems, it’s important to get medical advice early and follow the monitoring or recommended treatments. Early action can help ensure your child’s long-term health and well-being. Early treatment, typically with a surgical procedure called orchidopexy, can help address these risks and improve long-term health outcomes.
When Should Surgery Be Considered?
If the undescended testicle has not descended by the time your child is 6 months old, surgery is usually recommended to move the testis into the scrotum.
The procedure, known as orchidopexy, is typically recommended to be done before 12-18 months of age, ideally while the boy is still in nappies.
Please visit our Orchidopexy Surgery page for more detailed information on this procedure.