Undescended Testicle

During development in the womb, the testicles first form on the back wall of the abdomen. Then, under the influence of a number of hormonal and mechanical factors, they move downward, pass through the inguinal canal and reach the scrotum. This descent is completed during the last three months of pregnancy or shortly after birth.

If the testicles are not in the scrotum in a newborn baby, there may be 3 reasons for this:

The testicles may not have completed their descent from the abdomen and may have stopped at some point in the inguinal canal or inside the abdomen. This is called an undescended testicle.

The testicle may never have developed or may have disappeared while in the womb.

The testicle is not located anywhere along the normal path of descent but has settled in a different location (ectopic testicle)

What Is a Retractile Testicle?

In some children, testicles called retractile testicles may be seen, which sometimes descend into the scrotum and sometimes move back up. This is caused by overactivity of the cremaster muscle, and the approach differs from that for an undescended testicle. Distinguishing a retractile testicle from an undescended one must be done by a specialist physician. One third of these cases turn into undescended testicles over time, so they should be kept under close follow-up.

How Common Is an Undescended Testicle?

It is one of the most common genital anomalies, seen in 1-4% of full-term babies and in up to 45% of premature babies. In the first 3 months after birth, 70-77% of undescended testicles descend into the scrotum on their own. After the sixth month, the chance of spontaneous descent is very low (6%).

What Causes It?

Although the causes of undescended testicles are not fully known, a number of genetic and environmental factors (such as hormonal disruptors) are thought to be responsible.

What Are the Risks of an Undescended Testicle?

An undescended testicle may predispose to infertility or the development of testicular cancer later in life. It is sometimes accompanied by an inguinal hernia. The earlier the testicle is brought down, the lower the risk of developing infertility. Whether the risk of cancer is reduced is debated, but a tumor developing in a testicle that has been brought down is easier to detect by physical examination.

How Is It Diagnosed?

First, a physical examination checks whether the testicles can be felt. If the testicle cannot be felt in the scrotum or groin on examination (20%):

It may be located inside the abdomen or at the opening of the canal (50-60%)

A small testicle within the canal (atrophic or rudimentary) (30%)

The testicle never developed or was lost later (20%)

Imaging methods (such as MRI or ultrasound) are of no value in making this distinction; laparoscopy is required. Laparoscopy is the viewing of the inside of the abdomen with an optical instrument inserted through a small opening.

Treatment

The recommended time window for treatment is between 6 months and 1 year of age. Waiting during the first 6 months is recommended because the rate of spontaneous descent is high. After the eighteenth month, the process of deterioration begins in the structure of the sperm-producing cells and testosterone-producing cells. For this reason, the 6-month to 1-year window is considered the ideal time. The most definitive treatment is surgery, in which the testicles are brought down into their place in the scrotum.

Because of its low success rate (20%) and side effects (hair growth, negative effects on sperm cells, etc.), hormone therapy is no longer widely preferred today.