Europe South Asia Asia Pacific Americas Middle East Africa BBC Homepage World Service Education

Front Page



UK Politics







Talking Point
On Air
Low Graphics

Wednesday, October 14, 1998 Published at 17:56 GMT 18:56 UK


Infertility linked to bacterial infection

Scientists blame bacteria for some infertility

Some men have low fertility because of bacterial infections in their sperm, scientists have claimed.

The research suggests that a course of antibiotics may help to treat infertile men without the need for In Vitro Fertilisation (IVF) techniques.

Researchers from Hungary have shown that bacteria can prevent sperm from swimming well enough to reach an egg and fertilise it, New Scientist magazine reports.

Up to two thirds of men carry bacterial infections in their reproductive systems.

But in most cases the infections go unnoticed unless extremely large numbers of bacteria are present, in which case they can cause pain and discharge.

The Hungarian researchers isolated two types of bacterium, Fusobacterium nuclentum and Bacteroides fragilis, from 43 infected men, and tested their impact in different concentrations on sperm samples.

Stopped swimming

[ image: Antibiotics may be a cure]
Antibiotics may be a cure
Sperm usually swim in a culture medium for a day or more. But even in samples with low concentrations of the bacteria, only one per cent of the sperm were still moving after 18 hours.

In samples with the highest concentrations of bacteria - amounts found naturally in some men - all the sperm stopped moving after just three hours.

Dr Bela Molnar of Albert Szent-Gyorgyi Medical University in Szeged, said there were several possible reasons why the bacteria may impede the movement of sperm.

They might compete with the sperm for supplies of fructose, a sugar solution that sperm need for energy; they might produce a toxin that poisons the sperm, or they might physically interfere with the lashing of sperm tails.

Dr Molnar suggests that infertile men should undergo a treatment of antibiotics before IVF is considered.

"We should first treat them and let the try to conceive the normal way, " he said.

Professor Ian Craft, director of the London Fertility Centre, said he was thinking of introducing a course of antibiotics for all patients as standard procedure.

"A course of prophylatic antibiotics before assisted conception could help to prevent infection in some men. It could also solve any problem of sub-acute infection of the fallopian tubes in women," he said.

Professor Craft said antibiotics had not been given as standard because failure to fertilise an egg was "extremely rare" among men with good sperm counts.

Advanced options | Search tips

Back to top | BBC News Home | BBC Homepage | ©

Health Contents

Background Briefings
Medical notes

Relevant Stories

09 Oct 98 | Health
Shaping up to be a dad

22 Jun 98 | Health
Fertility funding frustrates medical staff

21 May 98 | Latest News
Fertility technique may result in mentally impaired children

Internet Links

In Vitro Fertilisation

Anaerobic bacteria

Fertility Awareness and Natural Family Planning Service

The BBC is not responsible for the content of external internet sites.

In this section

Disability in depth

Spotlight: Bristol inquiry

Antibiotics: A fading wonder

Mental health: An overview

Alternative medicine: A growth industry

The meningitis files

Long-term care: A special report

Aids up close

From cradle to grave

NHS reforms: A guide

NHS Performance 1999

From Special Report
NHS in crisis: Special report

British Medical Association conference '99

Royal College of Nursing conference '99