Undescended Testis refers to a testis that is not inside the scrotum at birth. The testes normally develop in the abdomen and gradually move down into the scrotum through a narrow passage known as inguinal canal during pregnancy.

The two testes move down at different rate but this ‘journey’ is usually completed around 36 weeks of pregnancy. Therefore, this condition is rare in full term babies but common in preterm babies. In most cases, only one testis has remained undescended at birth.

The undescended testis is usually stuck along the tract, usually in the groin, on its journey down to the scrotum. Occasionally, the two testes may be affected.

The testes are naturally suspended outside the body (in the scrotum) because they function at a slightly lower temperature than the core body temperature.

When left inside the body (i.e. undescended), the higher body temperature interferes with its proper development, functions of hormone and sperm production.

Patients with this condition have been found to be more predisposed (than the general population) to developing testicular cancer later in life.

Diagnosis of undescended testis – Undescended testis is usually noticed at birth when the baby is being examined by doctors after delivery. During this examination, the scrotal sac at the side where the testis has not descended will be empty.

Following this, effort is made to locate it along the channel of movement. It may be found along the tract towards the inguinal canal. If it is still beyond this level at delivery, it may not be easily located.

Ultrasound or laparoscope (an instrument used to view internal abdominal organ) may be necessary to locate it. 

The possibilities when the testis is not found in the scrotum include: 

1. Testis getting stuck along the tract on its way down to the scrotum.
2. One or both testes may not have been formed.
3. The testes may have formed but disappeared along the line during development.

Whichever of these is the case, prompt diagnosis and treatment are important to reduce the complications that may result from it.

Risk factors for Undescended Testis - The exact cause of undescended testis is not clear. However the following have been identified as risk factors for it:

1. Preterm delivery / low birth weight.
2. Genetic defects in the baby resulting in hormonal deficiency.
3. Cigarette smoking and alcohol use by the mother during pregnancy.

Complications of Undescended Testis - When testes remain inside the abdomen or close to the abdomen (in the groin), they are exposed to higher temperatures. This may result in:

1. Infertility due to low sperm count. This is because the testes cannot function optimally at the normal body temperature.
2. Testicular cancer – the high temperature the testis is subjected to, when not descended, damages the genetic materials of the cells and makes them susceptible to abnormal multiplication, resulting in cancer. The higher along the tract the testis is located, the greater the tendency to develop cancer. So a testis located in the abdomen has more potential to develop cancer than that located in the groin.
3. Trauma – due to the prominence of the bones in the groin, a testis lodging there could be damaged by the pressure from the surrounding bones.
4. Torsion – this refers to the twisting of the spermatic cord thereby cutting off blood supply to the testis and damaging the nerve contained in it. Torsion of the testis is common in this case than in normal testis because the testis has more room to move around, being not attached to the scrotum. Testicular torsion is an emergency condition, very painful due to nerve involvement and must be attended to fast; otherwise, the person may lose the testis.

Treatment - In most cases, undescended testis usually corrects itself. Within the first three months of life, the affected testis usually descends into the scrotum to occupy its natural position.

So, there may not be need for any form of treatment. It is therefore advisable for parents to wait and monitor the progress of the testis. This should be done in conjunction with consultation with your child’s doctor.

If the testis has not descended into the scrotum by the end of the fourth month after delivery, surgery may be needed to bring it down into the scrotum, as it may not descend automatically after that.

This surgery is better done before the child is eighteen months old. Leaving it for longer than that may damage the cells of the testis and predisposes it to some of the earlier mentioned complications.

The surgery involves bringing the testis down to the scrotum and fixing it there. Your child’s doctor will counsel you more on this.

Prevention - As the cause of undescended testis is not known, specific prevention may be difficult. However, since risk factors such as cigarette smoking and alcohol intake during pregnancy have been shown to contribute to its occurrence, avoiding these risk factors may help in reducing the incidence of undescended testis.

Though babies are examined after delivery when cases of undescended testis can be discovered, mothers are encouraged to examine the scrotal sac of their male babies and report early if the two testes are not present in the scrotal sac.