The testis is responsible for sperm production in men. The general body temperature is 36.9o C. But sperm production is best at a temperature 2o less than this level. This is the reason why the testes are located outside the body.
When the baby is formed in the womb, the testis is initially formed inside the baby’s belly. As the fetus (baby in the womb) grows, the testes gradually descend out of the body and reach the sac (scrotum). When this does not happen, or is arrested half way, the result is ‘Undescended Testis’ (UDT).
- How common is Undescended Testis? Is it possible for the testis to descend by itself?
- How is it detected?
- What happens when Undescended Testis is not corrected?
- What is the right time to operate and bring down the testis (Orchidopexy)
- What are the complications of Orchidopexy?
- What are the chances of fertility after operation?
- What is a retractile testis?
- Can a normally descended testis go back up?
How common is Undescended Testis? Is it possible for the testis to descend by itself?
Undescended Testis is seen in 30% of boys born before date (preterm). In such cases it is very likely that testis can descend by itself in 3-6 months time. Among full term boys 1-3% are found to have Undescended Testis. They also have a small chance to correct this problem by themselves. But this possibility becomes much less after 6 months of age, after this age surgery is required to correct it.
How is it detected?
When the newborn baby is examined by the paediatrician, by feeling with hands one can find out that the testis is missing. When the sac (scrotum) is poorly formed, one can suspect this. Also parents can detect it in a similar way when bathing the child. When the testis is not there, one can wait for 3-6 months for spontaneous descent. If this does not happen, it is essential to consult a Paediatric Urologist.
What happens when Undescended Testis is not corrected?
- Infertility: As mentioned before, sperm production takes place at a lower temperature than body temperature. When testis is not descended, it is exposed to higher body temperature, and sperm production is affected. In later life these patients have much reduced sperm count and chance to father (50-70% less than normal).
- Twisting of Testis (Torsion): When the testis is not descended, it is very free to move around itself. This makes it easy to twist and cut off its own blood supply; the result being loss of testis.
- Testicular Tumor: There is a small risk of tumor development in Undescended Testis. By doing an operation to bring it down this can be easily checked out. If the testis is not brought down, tumor can develop without being noticed and can become advanced before treatment.
What is the right time to operate and bring down the testis (Orchidopexy)?
For the children with Undescended Testis, it is recommended to have surgical correction within one year to prevent infertility in later life. During this operation, the testis is found at the lower part of the belly and fixed to the testis after achieving enough length. When the testis is developed poorly, it may need to be removed. Some times the testis is absent by birth. Laparoscopy is essential in such situations. Also when the testis is too high, two-stage operation may be needed. During the first stage the blood supply to the testis is cut off using a laparoscope. As the testis develops new blood supply, it is brought down at a second stage. All these need to be carefully decided by the Paediatric Urologist.
What are the complications of Orchidopexy?
In general in 95% of such operations there is a successful outcome. In 5% the following complications can occur.
- Testis being small (Atrophy): This can result because of damage to the blood supply during the operation. This can also be a result of testis being small by birth.
- Testis going back up (Ascent): When the length is not enough and the testis is under tension, testis can go back high again.
What are the chances of fertility after operation?
When only one testis is affected, and surgery is performed at the right time, there is 80% chance for fertility and paternity. When both testis are affected, if the surgery is performed at the right time, there is still 50% chance for fertility and paternity.
What is a retractile testis?
Sometimes the testis intermittently disappears upwards. This phenomenon is called ‘retractile testis’. In this situation one can wait for the boy to grow, however a careful followup is essential. On regular followup checks if the testis prefers to stay higher or if the testis is under tension when brought down, surgical correction is recommended.
Can a normally descended testis go back up?
In some boys who had normal testis at birth, at a later age the testis can go back up. This is called ‘ascending testis’. This is due to increased activity of a muscle around the cord. Although it can be an intermittent phenomenon, in some boys, the testis preferentially stays higher exposing them to high temperature. These patients need to be carefully selected for surgery.
- Undescended Testis is found in 3% of term boys and 30% of preterm boys.
- When the testis does not come down by it self by 6 months, it is essential to consult a Paediatric Urologist with a view to correct.
- When left uncorrected, complications like infertility and torsion can result.