Older sperm donors 'just as good'

Dr Meenakshi Choudhary told the BBC: "It doesn't matter up to the age of 45 years, there was no decline observed in this study.

"Sperm donors are a select group of the population, they are healthy fertile donors who go through a stringent recruitment criteria.

"Based on this we can say that age does not matter as long as the sperm quality is good."

'Men not invincible'

Dr Allan Pacey, a senior lecturer in sperm at the University of Sheffield, said men should not be tempted by complacency.

He told the BBC: "I think there is a perception out there that men are invincible from reproductive ageing - we just need to look at Charlie Chaplin who was 73 when he had his eleventh child.

"We know that as men go above the age of 40 and go into their fifties, their chances of getting a woman pregnant does reduce as a consequence of age.

"I don't think you can take this data and apply it uncritically to the general population, the advice would still be you should be trying to have a child before the age of 40 or 45."

Stem cell sperm 'fertility hope'

The scientists were able to coax stem cells into early sperm cells

Japanese researchers successfully implanted early sperm cells, made from the stem cells, into infertile mice.

The working sperm which they made was then used to father healthy, and crucially fertile, pups, Cell journal reports.

A UK expert said it was a significant step forward in infertility research.

'Landmark achievement'

The Kyoto University team were able to turn mouse embryonic stem cells into early sperm cells called primordial germ cells (PGCs).

When these were transplanted into infertile mice, the animal played "host" as the stem cells developed into normal-looking sperm. This was then used to successfully fertilise eggs.

Continue reading the main story“Start Quote"This has huge implications for furthering our understanding of how sperm are made, but may also one day lead to a clinical application whereby we could make sperm for infertile men."”

End QuoteDr Allan Pacey,University of Sheffield These eggs were then transplanted into a female mouse and healthy offspring were born who grew into fertile male and female adult mice.

The team, led by Mitinori Saitou, suggest the same procedure could be carried out using stem cells derived from adult skin cells.

Dr Jane Stewart, a spokeswoman for British Fertility Society and consultant gynaecologist at Newcastle Fertility Centre said the ability to generate gametes (reproducing cells) or gamete producing cells in the lab would be a "landmark achievement in the understanding and potentially treatment of fertility problems".

She added: "This publication in an animal model marks a further step towards this goal.

"However, as the authors clearly point out, much work remains to be done before we have a full understanding of such biological processes and indeed the implications of undertaking them in the lab."

Dr Allan Pacey, senior lecturer in Andrology at the University of Sheffield said: "Many research groups have attempted to re-create the process of sperm production in the laboratory using stem cells as the starting material.

"This has huge implications for furthering our understanding of how sperm are made, but may also one day lead to a clinical application whereby we could make sperm for infertile men."

But he added: "Sadly, so far, none of the attempts to make sperm from embryonic stem cells have been hugely successful, although we have learned much about some of the cellular processes involved.

"Furthermore, most of the attempts to use sperm-like cells have lead to the birth of unhealthy offspring which have quickly died."

But he said the Kyoto paper was "quite a large step forward" in developing a process by which sperm could be made for infertile men, perhaps by taking as a starting point a cell from their skin or from something like bone marrow.

He added: "Clearly more work needs to be done to refine this process, but it's hugely exciting."

'More pay' call for sperm donors

Payment for donors is under review Men who donate sperm for IVF should possibly be reimbursed more than women who donate eggs, a leading fertility campaigner has suggested.

Laura Witjens, who chairs the UK's National Gamete Donation Trust and has donated her own eggs, says most people are not aware of the "serious commitment" involved in sperm donation.

She argues it is wrong to see it as less worthy than egg donation.

Continue reading the main story Scrubbing Up 'Why sperm donors should be paid more' 'Cutting targets saves lives' Hidden cuts Interpreting need But fertility experts say donating eggs is invasive and carries greater risks.