Sperm boost may aid fertility

Adding three naturally-occurring chemicals to semen could help defective sperm fertilise an egg, according to experts.

The latest research project has discovered that a combination of the two helps sperm "switch on" - become ready to break through the membrane surrounding the egg.

This "switching on" process is known as capacitation.

They also prevent a reaction which can make the sperm infertile before it reaches the egg.

Adding chemicals to try to improve sperm performance is no novelty. Caffeine is among the substances put into semen to liven them up.

This is thought to be the first such treatment for problems with capacitation, as opposed to "motility", the ability of the sperm to move.

The combination was discovered at King's College and Queen Mary and Westfield Colleges in London.

All three are already found in semen, but the researchers, led by Professor Lynn Fraser, simply increased their quantities.

ICSI treatment

It has two possible applications - either to be added to the liquid used as the site for egg fertilisation in IVF treatments, or to improve the chances of successful insemination using sperm from men with low sperm counts, or defective sperm.

Most men in this situation are offered a technique in which a single sperm is taken and injected directly into the egg - this is called ICSI.

Professor Ian Craft, from the London Fertility Centre, described it as an "interesting idea", but suggested it would only be useful in borderline cases.

"It may improve the performance of sperm so that ICSI is not necessary," he said.