Undescended testicles are a common childhood condition where a boy is born without both testicles in his scrotum.
It is estimated that about one in every 25 boys are born with undescended testicles.
In most cases, no action is necessary – the testicle(s) will move down into the scrotum naturally during the first three to six months. However, a small number of boys have testicles that stay undescended unless treated.
The medical term for having one or two undescended testicles is unilateral or bilateral cryptorchidism.
When to seek medical advice
While undescended testicles do not present any immediate health problems, you should see your GP if at any point you notice your child's testicles are not in the normal place within the scrotum.
What causes undescended testicles?
During pregnancy, the testicles form inside the baby’s abdomen (tummy), before slowly moving down into the scrotum from about two months before birth.
Undescended testicles are where the testicles do not move into the scrotum by the time the baby is born.
It is not known exactly why some boys are born with undescended testicles and others are not, although having a low birth weight, being born prematurely (before the 37th week of pregnancy) and having a family history of undescended testicles have all been identified as risk factors.
Diagnosing undescended testicles
Undescended testicles usually have no symptoms other than not being able to feel the testicles in the scrotum. Your child will not normally experience any pain.
Undescended testicles are often diagnosed during a physical examination soon after a baby is born. This can usually determine whether the testicles are:
palpable – can be felt just above the scrotum
unpalpable – cannot be felt because they are higher up in the groin or abdomen
The majority of undescended testicles are palpable.
In some cases further tests are needed to determine the exact position of the testicle(s), such as a type of 'keyhole surgery' called a diagnostic laparoscopy.
How undescended testicles are treated
In most cases, the testicle(s) will move down into the scrotum naturally during the first three to six months of the baby’s life.
If the testicle(s) do not descend by this time, treatment is usually recommended. This is because boys with undescended testicles may have fertility problems in later life and an increased risk of developing testicular cancer, although this risk is still very small.
If treatment is recommended, this will usually involve an operation called an orchidopexy to move the testicle(s) into the correct position inside the scrotum. This is a relatively straightforward operation with a good success rate.
Surgery is usually carried out before your child is two years old. If the condition is treated at an early age, the boy’s fertility should be unaffected.
In a small number of cases, it may be possible to use artificial hormones to stimulate the descent of the testicles.
In most boys, the testicles can move in and out of the scrotum at different times, usually changing position as a result of temperature changes or feelings of fear or excitement. This is a separate condition from undescended testicles, and is known as retractile testicles.
Retractile testicles in young boys are not a cause for concern, as the affected testicles(s) often settle permanently in the scrotum after puberty.
See your GP if you notice your child's testicle(s) are not within the scrotum. Your GP can carry out an examination to determine whether your child's testicles are undescended or retractile.
Causes of undescended testicles
It's not known exactly what causes undescended testicles, but they are thought to occur if something disrupts the normal development of the testicles.
Normally, once the testicles have formed, they stay inside the baby’s abdomen (tummy) until about two months before birth. At this point, they start to gradually descend from the abdomen into the scrotum, finally settling in the scrotum shortly before birth.
The descent of the testicles is a complex process that is influenced by a number of factors, including certain hormones and the pressure within the abdomen. If there are any problems affecting these, there is a risk of the testicle(s) not descending.
Most boys born with undescended testicles are otherwise completely healthy and no reason for their condition is identified.
Who's most at risk?
It is not known exactly why some boys are born with undescended testicles, but several things have been identified that increase the risk of a baby boy having the problem. These include:
Low birth weight – boys with a birth weight of less than 2.5 kg (5.5lb) are more likely to be born with undescended testicles than those with a normal birth weight.
Being born prematurely – the earlier a boy is born, the more likely he will be born with undescended testicles.
Having a family history of undescended testicles – having an older brother with undescended testicles means that a boy is more likely to be born with the condition compared with the general population.
Diagnosing undescended testicles
Undescended testicles are usually diagnosed soon after the baby is born or during a routine check-up when they are six to eight weeks old.
The first stage in diagnosing undescended testicles is to carry out a physical examination to see whether the testicles can be felt near the scrotum (palpable) or if they cannot be felt at all (unpalpable).
The physical examination can sometimes be difficult, and your doctor may refer your child to a paediatric surgeon to help with getting the right diagnosis.
In some cases, a number of further tests may also be carried out to locate the affected testicles(s) and check for any related problems (such as abnormal hormone levels).
These tests may include an ultrasound scan, a diagnostic laparoscopy (see below), and urine and blood tests (in rare cases).
A procedure called a diagnostic laparoscopy may be needed to find an unpalpable testicle. Diagnostic laparoscopy is a type of 'keyhole surgery' that uses an instrument called a laparoscope inserted through a small incision usually made in the belly button (so it is hard to see afterwards).
A laparoscope is a small tube containing a light source and a camera. The camera relays images of the inside the abdomen (tummy) or pelvis to a television monitor.
Depending on where the testicle is located, it may be possible to perform surgery immediately to reposition the testicle into the scrotum.
Treating undescended testicles
Undescended testicles will usually move down into the scrotum naturally by the time your child is three to six months old. In some cases, this does not happen until your child is six to 12 months old.
If the testicles do not descend by your child's first birthday, it is very unlikely they will do so without treatment.
If treatment is necessary, surgery to reposition the testicle(s) into the scrotum is usually recommended. This type of surgery is known as an orchidopexy.
Ideally, surgery should be performed before your child reaches two years old. This is because waiting longer than this may increase a boy’s risk of developing fertility problems or testicular cancer later in life.
In most cases, an orchidopexy involves first making an incision (cut) in the groin to locate the undescended testicle. The testicle is then moved downwards and repositioned in the scrotum using a second incision.
A type of keyhole surgery known as a laparoscopy is sometimes carried out first to locate the testicle if it is higher in the abdomen (tummy). This involves passing a laparoscope (a small tube that has a light source and a camera) through a small incision in your child's abdomen. The laparoscope relays images of the inside of the abdomen to a television monitor.
When the procedure is complete, the incisions are usually closed with dissolvable stitches that don't need to be removed at a later date.
Orchidopexies are performed under a general anaesthetic, which means your child will be asleep during the procedure and will not feel any pain while it is carried out.
The operation usually takes about 40 minutes and is usually performed as day surgery, which means your child will be able to return home on the same day.
Your child may feel a bit unwell for the first 24 hours after surgery. Feelings of nausea are a common side effect of general anaesthetic. They are nothing to worry about.
The following advice should help to speed up your child’s recovery time and reduce their risk of having any post-operative complications:
Your child will need to have regular pain relief for a few days after the operation. Activities such as playing games, watching television and reading together may help to keep his mind off the pain.
Encourage your child to drink plenty of fluids.
Your child’s groin area may feel sore for a while after the operation. Wearing loose-fitting clothing will help, although wearing nappy is fine and can help protect the area.
Follow your surgeon’s advice about washing and bathing.
Your child should not ride a bicycle or use "sit-on" toys for a few weeks after the operation. This is to prevent the testicles travelling back up into the abdomen. Ask your surgeon for their advice about this.
Your child should rest for a few days at home before returning to school or nursery.
When to seek medical advice
Be alert for any signs that the site of the surgery has become infected. These include:
Your child being in a lot of pain, and the prescribed pain relief not working.
Your child having a high temperature (fever) of 38°C (100.4°F) or above.
The site of the surgery being red, inflamed or feeling hotter than the surrounding area.
A discharge of fluid or pus appearing from the site of the surgery.
If you notice any of these signs and symptoms, contact your GP as soon as possible for advice.
Results of surgery
As a general rule, the closer the testicle is to the scrotum, the more likely surgery will be successful.
The success rate for treating palpable testicles located near the scrotum is estimated to be up to 90%.
The operation is slightly less successful in treating unpalpable testicles, depending on where the testicle is located. If the testicle is particularly far from the scrotum, two separate operations may be needed to complete the repositioning.
Risks of surgery
As with any type of surgery, an orchidopexy carries the risk of complications, some of which may need to be treated with further surgery.
Possible side effects and complications of an orchidopexy include:
bleeding, swelling or bruising where the incisions were made
the wound becoming infected
the testicle moving up into the groin again
testicular atrophy – where blood supply cannot sustain the testicle in its new position, which causes the testicle to wither away
damage to the tube connecting the testicle to the urethra (vas deferens), which can make it difficult for sperm to pass through
Complications are more likely to occur after surgery to correct unpalpable undescended testicles.
Alternatives to surgery
An alternative to surgery is to use synthetic hormones that encourage the testicle move into the scrotum.
Hormone therapy is usually only recommended if your child’s testicle(s) are close to the scrotum. This is because the treatment is usually ineffective in treating unpalpable testicles that are located higher up.
Hormone therapy may also be recommended if both testicles are undescended and blood tests have shown that this is due to underlying problems with their hormones.
However, hormone therapy is less commonly used than surgery because it is effective in less than one in every five cases and there is a possible risk of long-term side effects. If hormone therapy is unsuccessful, surgery will usually be required.