Sperm counts are so inaccurate that prospective parents are being given the wrong advice about fertility techniques, researchers have claimed.

A team of experts from Sheffield University plans to launch a website to help students and lab workers improve their analytical technique.

The Sheffield team decided to develop the training aid after carrying out a survey of the accuracy of sperm tests carried out at sperm counting centres around the country.

Sperm samples must be kept frozen

Dr Allan Pacey, who worked on the study, said: "The data which is available currently suggests that a man who has his sperm counted in different institutions may have a wildly different count depending on where he goes.

"I must say the situation is slowly improving, but only a couple of years ago it was possible that a man going to one laboratory would be told that he was infertile, whereas in another laboratory he was told that he was perfectly okay."

Checking a man's sperm is not just a question of seeing how much there is, but also what it is like.

Variety of treatments

Consultant gynaecologist Professor Bill Ledger said: "We have a variety of treatments for different problems, so the purpose of doing a sperm test is to work out whether there is a problem and if so how profound it is.

"At one end of the spectrum chaps with a very severe problem have to go into in-vitro fertilisation with ICSI, the sperm injection technique, milder forms of sperm dysfunction can be treated with simpler treatments."

Dr Alan Pacey has developed a website

Dr Pacey has written a CD-ROM that shows students how to count sperm, and how to recognise healthy sperm by how fast they move, their relative size and their overall shape.

He said: "The idea is to try to make some of this material available on a website so that people can log in wherever they are in the world and find out whether their interpretation of a given semen sample is what it should be and within a matter of seconds they can get an answer by e-mail."

Professor Bill Ledger said the website could help people have children at less emotional and financial cost.

The website is due to go on line later this year.