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Last Updated: Friday, 28 April 2006, 01:03 GMT 02:03 UK
Male contraceptive 'reversible'
Hormonal contraceptives can be given as an injection
Male hormonal contraception can be reversed within a few months, a study has found.

Researchers looked at data on more than 1,500 men around the world who had taken part in tests of some form of hormonal contraception.

On average, men took three to four months to recover full fertility, according to a paper in the Lancet.

Experts say the research offers men reassurance that their fertility can be restored.

These findings thereby increase the promise of new contraceptive drugs allowing men to share more fairly the satisfaction and burden of family planning
Dr Peter Liu, Los Angeles Biomedical Research Institute

Existing methods of contraception for men - condoms and vasectomy - may be unacceptable to some couples because they are not sufficiently reliable or not easily reversible.

Male hormonal contraception methods work in a similar way to those used by women.

While female treatments suppress ovulation, sperm production can be prevented by giving the male hormones androgen and progestagen.

These can either lead to no sperm being produced in semen, or very low sperm counts too low to lead to conception - fewer than three million sperm per millilitre compared to a fertile level of 20 million.

Two treatments - one injection and one implant - are currently being tested in advanced clinical trials.

'It is reassuring'

Dr Peter Liu, from the Los Angeles Biomedical Research Institute, looked at 30 studies into male hormone contraceptives.

He found that men who had used some form of sperm suppressant contraception for a year took an average of three to four months to return to fertile levels of sperm production

Older age, being of Asian origin, shorter treatment duration and higher sperm concentrations prior to hormone treatment were all linked to faster rates of recovery.

Dr Liu said: "Our data provide strong assurance that the previously described efficacy of hormonal male contraceptives is coupled with highly predictable recovery to sperm characteristics that are compatible with fertility.

"These findings thereby increase the promise of new contraceptive drugs allowing men to share more fairly the satisfaction and burden of family planning."

David Baird, professor of reproductive endocrinology at the University of Edinburgh said: "This shows that, although there is a bit of variation between individuals, men get fertility back in three to four months.

"It's what we've all suspected, but it's nice to see it shown. It is reassuring."

He said research carried out by his team, looking at couples in Edinburgh, Africa and Asia, had found the majority of men would use hormonal contraception - and the majority of women would trust their partners to do so.

However, far fewer women said they would trust men in general to use the contraceptive.

Toni Belfield, of the Family Planning Association, said: "It's important that research continues to provide a range of options for both men and women in order that good confident choices can be made.

"It will be good news when the method is finally available, although this will be some years away."

How the research could lead to a new form of family planning


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