Undescended testicle: symptoms, causes, surgery and when it is treated

Before a baby boy is born, the NHS explains, the testicles grow inside the tummy and later move down into the scrotum. Sometimes one or both do not move into the usual place. That is an undescended testicle (also called an undescended testis, or cryptorchidism).

NICE Clinical Knowledge Summaries (CKS) define it as incomplete descent of one or both testes from the abdomen through the inguinal canal, with absence from the scrotum. About 80% of undescended testes can be felt (they are palpable).

A retractile testicle is different. CKS call it a normal variant: it can be moved into the scrotum but may pull back up. It still needs follow-up, because there is a significant risk of an ascending testis.

The NHS says the main symptom is not being able to feel 2 round glands (testicles) inside your child's scrotum. You may only be able to feel 1, or neither. Undescended testicles are usually found at the newborn physical examination, which usually happens in the first few days after birth.

CKS note that routine examination for undescended testes takes place in the UK as part of the newborn and infant physical examination screening programme, at birth and at 6 to 8 weeks. The NHS says see a GP if you think you or your child may have undescended testicles, or if you notice any changes in the testicles that are not usual.

The NHS says undescended testicles often move into their usual place in the first 12 weeks. If only 1 testicle is affected and it has not moved within 4 to 5 months, your child will usually be referred to a specialist. If both are affected, referral may be sooner, usually after 8 weeks.

Your child may need surgery to move the testicle to the correct place, called orchidopexy. The NHS says surgery will usually be done when your child is around 1 year old, and that it is safe and effective. The surgeon will explain what happens and what to expect.

CKS advise primary care to refer to paediatric surgery or urology, to be seen by 6 months of age, to consider surgery if the testicle remains undescended. They say evidence suggests that correction in the first year of life is more protective than later treatment.

If untreated, the NHS says undescended testicles can cause your child health problems. CKS say successful surgery reduces the risk of the complications but does not prevent them.

The table brings together the timings given by the NHS and CKS. Your own child's timing is set by their doctor.

The NHS says it is not always known what causes it. Your baby may be at higher risk if they were born prematurely (before the 37th week of pregnancy), have a low birth weight or have relatives who had undescended testicles. Sometimes it can be caused by another condition, but this is rare.

CKS add endocrine disorders such as congenital adrenal hyperplasia and disorders of sexual development as risk factors, and note that maternal smoking, alcohol use and diabetes are possible ones. Suspected disorders of sexual development, or both testes being impalpable at birth, need urgent senior paediatric review within 24 hours.

CKS describe an association between a history of undescended testes and reduced fertility. Testes that stay at a higher temperature in the abdomen or groin may suffer germ cell damage. The effect is greater if both are undescended. CKS give approximate paternity rates of about 90% for boys with one undescended testis (compared with 94% for those with normally descended testes), and 33 to 53% for those with both affected. Earlier surgical correction improves subsequent fertility potential.

CKS say cryptorchidism is a significant risk factor for testicular cancer. Those without surgical correction, or treated after the age of 10, have about a six-fold higher risk. Those treated before puberty still have about a two-fold increased risk. The chance of later testicular cancer is around 1 in 120 for those born with a unilateral undescended testis and around 1 in 44 for bilateral. The risk is highest in intra-abdominal testes.

CKS advise boys and young men with a history of undescended testis to examine their testicles regularly during and after puberty.

Undescended testicles are not usually an emergency, but a sudden change is. CKS note that undescended testes may be more likely to twist (torsion) than scrotal testes. The NHS says to call 999 or go to A&E for sudden, unbearable pain in the testicles or tummy, as it could be a twisted testicle needing hospital treatment as soon as possible. Do not drive yourself; ask someone to drive you or call an ambulance.

See a GP promptly if you notice a lump, swelling or a change in shape in a testicle,. CKS list an associated inguinal hernia as a possible complication in some boys with undescended testes.

On the NHS, undescended testicles are picked up at the newborn examination and monitored by the GP and health visitor, then referred to paediatric surgery or urology if they do not descend. Waiting times to see a specialist and to have surgery vary by area, so ask your GP or the referral team what to expect.

Some families choose a private consultation with a paediatric surgeon or urologist. The checks, timings and operation described above are the same in either setting. Whichever route you use, make sure your child is seen by a surgeon who regularly treats children.