2 MINUTES ON... Undescended testicle.

Byline: DR MIRIAM STOPPARD Helping to keep you fit and healthy miriam@mirror.co.uk @MiriamStoppard

How testicles develop

The testicles grow and develop inside the back of the abdomen near the kidneys.

Shortly before a boy is born they move down or descend into their normal position in the bag of skin called the scrotum.

Why must they descend?

For testicles to develop normally at adolescence and produce sperm they must hang outside the body.

This is because sperm production can proceed only at a temperature that is slightly below the body's internal temperature.

How is an undescended testicle spotted?

When a baby boy is born, a paediatrician will examine his testicles to see if they have descended. If not, you'll be told and reassured that they may descend naturally.

What happens if they don't descend?

If the testicles - or more usually, one testicle - fail to descend, sperm won't be produced normally, but the hormone testosterone (which is responsible for maleness, such as a deeper voice and body hair) will be.

What might be done?

Your doctor will probably take action before your son is five or six years old. If a boy's testicles fail to descend, many surgeons recommend operating before the age of two.

An undescended testicle that is producing testosterone can increase the risk of testicular cancer if left in the abdomen.