Mark Jackson does not come across as your typical sperm donor.
He's 37, for one thing. For another, he's a stocky, blue-collar worker of average stature - not the archetypal college soccer recruit.
But Mr. Jackson is by no means an anomaly. With sperm donation no longer an anonymous act in Britain, not only have donor numbers fallen, but the profile of the average volunteer has totally changed.
For would-be parents with fertility problems, that's both good and bad news. It may be harder to find a donor, but that donor is more likely to be a middle-aged family man than a curious student keen to make some cash for the weekend - and wary of the prospect of actually meeting his offspring a few years down the road.
"In the old days, the classical recruiting ground was the medical school," says Gedis Grudzinskas, medical director at one of Britain's largest sperm banks, the Bridge Fertility Center in southeast London.
Now, he says, "These men don't seem to be concerned about anonymity because they are more mature and able to deal with someone coming up in 18 years time and saying, 'Hi Dad'."
Jackson says it's a positive development. "I would rather get people who really care to come forward to be donors," he says. "If I was a child born to a donor, I wouldn't want to be told my father was a student who just wanted the £15 fee to go out on a Saturday night."
Donor anonymity has been a hot-button issue in Europe for years. Several countries have scrapped it, including Sweden, Switzerland, Norway, the Netherlands, and Britain - in April of this year. The recent case of a boy of unspecified nationality who found his biological father using genealogy websites and an Internet DNA-testing service has underscored how fragile parental anonymity has become.
The big concern in Britain was that removing anonymity would decimate already feeble donor numbers. Indeed, one recent study showed a sharp fall in volunteers after 2000, when the anonymity question started to be debated. Official figures showed the number of donor insemination treatments fell from 25,000 a decade ago to 6,000 in 2003.
"The feeling was that losing anonymity was off-putting for someone who wouldn't know where they would be in 18 years' time," says Jane Stewart, a specialist in reproductive medicine at the Newcastle Fertility Centre.
The reduction in donors has had striking consequences. Several sperm banks have shut down, leaving several regions unserved and further discouraging potential donors in those regions from coming forward. (Jackson had to complete a 150-mile round trip each week for three months to contribute.) Other clinics have started importing sperm from the US and Denmark, where donor numbers are far higher.
One in seven British couples have fertility problems, not to mention thousands of women who want to conceive but have no male partner. Around 900 children are born through donor insemination in Britain each year. But to meet demand, clinics say that they need far more than the 250 donors who sign up annually. Without them, the implications for fertility treatment in Britain could be severe.
"There are people out there who accept their infertility, but a lot more want to experience their own pregnancy and want to try for a child by the means that are available," says Laura Witjens, chairwoman of the National Gamete Donation Trust charity, noting the psychological distress that experts say infertility can cause.
"It all comes down to how much you want to help other people. The donors coming forward now are fathers who try to imagine their lives without their children," she says.
The change in anonymity rules has been generally welcomed by those on the receiving end of the process. Though some parents are uncertain about how or whether to explain the truth to a donor- conceived child, Olivia Montuschi of the Donor Conception Network argues that offspring should be able to find out more about their genetic heritage.
She says her own 19-year-old daughter, Susannah, would love to know more about her biological father. "She's a 6-ft. blonde, much taller than both me and my husband. She wants to know what kind of a person he is, what values he holds in life, what kind of music he likes."
Would that be so bad for a donor father? There are, after all, now no financial or pastoral obligations at all in being identified. The donor is not even required to meet his progeny.
Jackson says the fears associated with being traced 18 years down the line are overblown.
"In 18 years' time, society will have changed that much that it won't be a big deal," he says. "It might just be curiosity, they might just want to see who the donor was, to speak to him and find out more about him.
"I'd have no problem whatsoever with that."
In 1992-93 there were more than 25,000 donor insemination treatments (using donor sperm); this had fallen to a little over 6,000 treatments by 2003-03.
• 1 in 5 of licensed fertility treatments involved the use of donor sperm, compared with almost half of treatments in 1994-95.
• 1 in 20 licensed fertility treatments involved the use of donor eggs, compared with almost 1 in 35 of treatments in 1994-95.
• 1 in 8 children born through licensed fertility treatment was born from donated sperm - this is equivalent to approximately 1 in 800 of all children born in Britain.
• 1 in 16 children born through licensed fertility treatment was born from donated eggs - equivalent to approximately 1 in 1600 of all children born in Britain.
• More than 2 out of 3 sperm donors (69 percent) were aged over 30.
• The most common age group for sperm donors was 36-40.
• More than 2 out of 5 sperm donors (41.5 percent) already had children of their own.
• Just under a third of sperm donors (31.4 percent) had two or more children.
All data from Human Fertility and Embryology Authority, the body that regulates fertility treatment in Britain.