However its chief executive Laura Witjens told The Guardian this week that it only has nine registered donors and to encourage more men to make a deposit a campaign will be launched later this month.
Witjens revealed that the drive will be inspired by the success of Danish sperm banks, which appeal to the male ego to boost their stocks.
"If I advertised saying 'Men, prove your worth, show me how good you are,' then I would get hundreds of donors," she said. "That's the way the Danish do it. They proudly say, this is the Viking invasion, exports from Denmark are beer, lego and sperm. It's a source of pride."
Witjens said the "superhero" message of her promotional campaign is a serious one, because ideally donors must have extremely strong sperm in order for it to have the best chance of surviving the process of freezing and thawing. This is partly why the bank has so few registered donors after almost 12 months, she said.
"If 100 guys enquire, 10 will come through for screenings and maybe one becomes a donor. It takes hundreds of guys. Getting an approved donor on the books requires a man to come to the clinic twice a week for up to four months, refraining from sex or masturbation for two days before each visit and then be tested again after six months."
Another issue is the unrealistic expectations of families seeking a donor, Witjens added, saying: "We get asked for six-foot tall donors, when the average height is 5 foot 7 inches in Britain, so you are effectively ruling out 90 percent of the donors. And they all want doctors or barristers, but the reality is the majority of those professionals have not got time. So you actually get young guys with flexible jobs."
A sperm sample costs £400 but the NHS covers the cost if patients meet the guidelines for free treatment.
Donors get paid £35 per session but Witjens said offering a larger monetary incentive might not have the desired effect: "We might get more donors if we paid £50 or £100 per donation. But money corrupts. If you feel you can make £200 a week for four months, you might hide things about your health."
Witjens refuted suggestions that the low number of donors indicates the failure of the bank, telling ITV News that those nine men can "help 90 families achieve their dream of having a child."
She also took the opportunity to dispel one of the biggest myths surrounding sperm donation — that biological fathers may end up being legally responsible for any future offspring conceived as a result.
A change in the law in 2005 lets children of sperm donors find out who their father was when they turn 18, if they wish to. However the father is under no legal or financial obligation to the child, who by then would be an adult in any case.
For more information visit The National Sperm Bank.
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