An undescended testicle (testis) is more common in boys who are born prematurely. Although in the majority of cases the testicle descends by the age of 6 months, some boys will need an operation. This is called an orchidopexy. This operation brings the testicle down from the tummy (abdomen) into the testicular sac (scrotum). There is an increased risk of infertility and also cancer if the testicle remains in the abdomen.
What is an undescended testicle?
In boys, the testicles (testes) begin their development in the tummy (abdomen). Whilst your baby is growing and developing in your womb (uterus), the testicles gradually travel down into the testicles' sac (scrotum). This usually happens towards the end of your pregnancy. At birth, most boys have two testicles in the scrotum. However, in some babies, one or both of the testicles cannot be felt in the scrotum. The testicle will then be undescended. This is also known as cryptorchidism. The testicle is usually stuck in the canal that leads from the abdomen to the scrotum (the inguinal canal) but sometimes it stays inside the abdomen.
Usually only one of the testicles is affected but, on rare occasions, both testicles fail to travel to the scrotum.
An undescended testicle is more common in premature babies, affecting around 3 in 10 premature babies. Around 1 in 20 male babies born at the normal time are born with an undescended testicle. Many of these will become descended in time. However, the testicle remains undescended in some children.
Very rarely, there may be an absent testicle which has not developed at all.
Can the testicle still descend after birth?
In some cases, the testicle (testis) that is undescended will still descend after birth. However, this is less likely the older your baby becomes. Both testicles (testes) should be in the testicular sac (scrotum) by the time your child is 1 year old.
How is an undescended testicle diagnosed?
This is usually found when your baby is examined, either shortly after birth or during the six- or eight-week baby check. This is found by examining your baby's testicular sac (scrotum) gently to feel for the presence or absence of the testicles (testes).
In some children, the testes may have descended to the scrotum but are not always able to be felt there. This is because the testes can sometimes rise back into the body, especially when your baby is cold. If you can feel both testes in the scrotum at other times - for example, when your baby is having a bath - then your baby does not have undescended testicles and does not need any treatment.
What symptoms does an undescended testicle cause?
Having an undescended testicle (testis) does not cause any symptoms at all. It does not cause pain.
Why is an undescended testicle a problem?
If one or both of the testicles (testes) are left in the tummy (abdomen) then they do not mature properly. The amount of sperm and fertility levels are lower in men who have had an undescended testicle (testis), especially if it was not treated early in childhood. This is because the testicles need to be a few degrees cooler than the rest of the body in order to produce sperm.
It is also impossible for men with an undescended testicle to check for testicular cancer, as an undescended testicle cannot be felt in the abdomen. There is a large increased risk of testicular cancer in men who have not had their undescended testicle surgically fixed. There is still a small increased risk in those men who had an undescended testicle fixed when they were younger.
Treatment for undescended testicles
If the child is under 6 months old when an undescended testicle (testis) is diagnosed then some time is usually given to see if it will descend on its own. The majority will descend on their own and do not need treatment. However, babies over the age of 6 months, with an undescended testicle, are usually referred to a specialist for treatment.
An undescended testicle is best treated in early childhood. Most can be felt in the inguinal canal, which leads from the tummy (abdomen) to the testicular sac (scrotum). They are usually treated by a short operation called an orchidopexy. This is an operation to bring the testicle down from the abdomen to its usual place in the scrotum. It is a short operation which is done under a general anaesthetic. It is usually possible for your child to go home on the same day of having the operation.
The orchidopexy can either be carried out using traditional open surgery or by keyhole surgery. The surgeon will move the testicle down into the scrotum and then close up the passage through which the testicle should have travelled. This stops the testicle moving back into your child's abdomen.
There are usually no long-term problems following an orchidopexy for an undescended testicle. However, boys who have had an undescended testicle in the past should be very vigilant about self-examination for testicular cancer when they are older.
Occasionally, men need treatment for an undescended testicle. The testicle can either be removed or orchidopexy can be performed. The type of operation will depend on the age of the man, the site of the testicle and whether there is a normal testicle on the other side.
Further reading and references
Chan E, Wayne C, Nasr A; Ideal timing of orchiopexy: a systematic review. Pediatr Surg Int. 2014 Jan30(1):87-97.
Undescended testes; NICE CKS, August 2014 (UK access only)
Cryptorchidism: The UK NSC policy on Cryptorchidism screening in newborn boys; UK National Screening Committee Policy Database, 2012
Leslie S et al; Cryptorchidism, StatPearls, 2018