Undescended testicles

Testicles (testes) are the male sex glands that produce sperm and sex hormones. Usually, both testicles sit in the scrotum. Undescended testicles means that one or both testicles are missing from the scrotum and are instead located in the groin or inside the lower abdomen. The condition is painless, and urination is not affected.

About five per cent of all boys are born with this condition. Premature and low birth weight babies are at increased risk. In about half of babies born with undescended testicles, the testicle reaches the scrotum within the first three months of life. If a testicle is still undescended at three months of age, the baby should see a pediatric surgeon.

In babies born at full term, undescended testes occur in around 1 in 100 to 1 in 20 newborns. In preterm babies, they can occur in up to half of all newborns.

Other terms for undescended testicles include empty scrotum, monorchism and cryptorchidism. A boy with the condition will have an empty scrotum on one or both sides.

Undescended versus retractile testicles#

Undescended testicles should not be confused with retractile (retractable) testicles. Retractile testicles normally sit inside the scrotum but tend to tuck back up into the body under certain conditions, for example when the boy is cold. Treatment is not necessary as long as the retractile testicles stay in the scrotum most of the time before puberty begins.

How the testicles develop#

The testicles form inside the abdomen of the male fetus. Between about 25 and 35 weeks of pregnancy, the testicles migrate down slender channels in the lower abdomen (the inguinal canals) and settle into the scrotum.

In most cases of undescended testicles, only one testicle is affected. In around one in ten cases, both are missing from the scrotum (bilateral undescended testes).

Premature babies are at increased risk because the migration of the testicles has not had time to happen before birth. Low birth weight babies also have a higher rate of undescended testicles. Around 17 per cent of male newborns weighing under 2.3 kg have undescended testicles, and the lower the birth weight, the higher the risk: nearly all male babies weighing under 907 g are born with the condition.

Problems associated with undescended testicles#

Undescended testicles are linked to a range of health problems, including:

• Hernia – a boy with undescended testicles is at increased risk of an inguinal hernia (an abnormal bulge in the groin).
• Infertility – the testicles sit in the scrotum because sperm production needs a temperature a few degrees lower than the body. Testicles that are not brought into the scrotum from a young age will not produce sperm. Even with surgical correction, men who had undescended testicles have higher rates of infertility.
• Cancer – the risk of testicular cancer is around five to ten times higher than in the general male population. This risk may remain even after corrective surgery, particularly if surgery is delayed until later in childhood. Testicular cancer usually occurs between the ages of 25 and 40 years.
• Trauma – an undescended testicle is at higher risk of injury.
• Testosterone (androgen) deficiency – having two undescended testes increases the risk of developing testosterone deficiency.
• Poor self-image – the appearance of the scrotum can affect a boy’s confidence and self-esteem.

Acquired undescended testicles#

Occasionally a boy’s testicles migrate back up into the body even though they were properly in the scrotum at birth. The suspected cause is that the spermatic cords, which attach each testicle to the body, fail to grow at the same rate as the rest of the child. The comparatively short cords gradually pull the testicles out of the scrotum and into the groin.

This is known as acquired undescended testicles, or acquired cryptorchidism, and it can occur in boys aged between about one and ten years. It may also occur in boys who were treated for undescended testes at birth: up to half of boys treated as a small infant develop acquired undescended testes later in childhood.

Diagnosis#

Undescended testicles are diagnosed by physical examination, usually at three months of age if the testicle has not descended into the scrotum by that time. In some cases, the missing testicle can be felt in the lower abdomen.

Because the acquired form can develop later, your child’s doctor should also check for it around the time he starts school, and it can occur up to around ten years of age. If you think your child’s testes may have moved back into his groin, for example if you cannot see them in the scrotum when he is in a warm bath, or he cannot feel them himself, see a doctor.

Treatment#

Surgery is the best treatment for undescended testicles. Ideally, the child should be aged between six months and one year at the time of surgery. Research suggests that future sperm quality in the affected testicle is reduced if the condition is corrected after the age of two. However, surgery is still possible at a later age, for example if the child develops acquired undescended testicles. About 10 per cent of males who have surgical correction experience reduced fertility later in life.

Surgery to relocate the testicle inside the scrotum is called orchidopexy. The procedure generally involves:

• a general anesthetic is given
• an incision is made in the groin to reach the testicle inside the inguinal canal
• the testicle is taken out of the inguinal canal
• the spermatic cord is ‘unkinked’ and gently stretched to its full length, cutting away any obstructive tissue if needed
• an incision is made in the scrotum, and the testicle is placed inside and stitched securely
• all incisions are then closed

Vanished testicle#

In about five per cent of cases, surgeons cannot find the missing testicle. It is thought that the developing testicle may have died in the womb because of an interrupted blood flow. A vanished (or absent) testicle is also associated with other birth defects of the urinary system, such as abnormal blood vessel networks to the tubes that carry sperm (the vas deferens).

Key points#

• About five per cent of boys are born with undescended testicles, and premature and low birth weight babies are at increased risk.
• The testicular cancer risk may remain even after corrective surgery, particularly if surgery is delayed until later in childhood.
• Surgery (orchidopexy) is the best treatment for undescended testicles.
• In a small number of cases the testicle has vanished, thought to be because it died in the womb due to an interrupted blood flow.

Where to get help#