The everyday infection that destroys sperm

The evidence that the UK's most-common sexually-transmitted infection can reduce male fertility as well as female fertility continues to mount.

Malehealth has covered the risks from chlamydia before but now a small study of men in Mexico has put numbers to the risk. Researchers examined 193 men. Those with chlamydia — 143 of them — had a lower concentration of sperm than those who did not and, most worryingly, had THREE times the usual number of genetically damaged sperm.

The good news is that antibiotics made a real differance — only 12.5% of chlamydia-infected couples conceived without them. At the end of the treatment, 85.7% had successfully become pregnant.

Allan Pacey, senior lecturer at the University of Sheffield and secretary of the British Fertility Society, told The Times: 'I would advise couples trying for a baby to be screened for chlamydia.'

One in ten men have chalmydia. It is the most common sexually transmitted infection in Britain. However, the real figure could be much higher as the disease often has no symptoms, and can remain undetected for years.

Chlamydia can be detected by a simple urine test. Postal kits cost £25 from Boots or a free national free screening programme exists for under-25s so ask your GP.

• FAQs on chlamydia in men
• Ten other ways to boost your fertility