Borrowing from successful campaigns in Denmark, which is one of the biggest exporters of donated sperm, Witjens is planning a 'superman' advertising campaign, appealing to male vanity.
'If I advertised saying "Men, prove your worth, show me how good you are", then I would get hundreds of donors,' she told The Guardian. '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.'
Based in Birmingham, the UK's national sperm bank was set up a year ago as a partnership between the National Gamete Donation Trust and Birmingham Women's Hospital to counter the shortage of sperm donors in the country. It was funded with a one-off government award of £77,000 but is now expected to be self-sustaining.
Demand for donated sperm has increased year on year, from same-sex couples as well as from older single women wanting children. As a result, one-third of donated sperm used in the UK is imported – mostly from the USA and Denmark.
Witjens says the 'superman' theme of the proposed recruitment campaign also has a serious side – donors must have exceptionally strong sperm that can survive the freezing and thawing process.
'If 100 guys enquire, 10 will come through for screenings and maybe one becomes a donor. It takes hundreds of guys,' said Witjens to The Guardian. Donors must come to the clinic twice a week for up to four months, and refrain from sex or masturbation for two days before each visit, before being tested again after six months.
Although donors receive just £35 per session, Witjens did not think that more money was the answer to the sperm shortage: '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.'
After the initial campaign at the end of September, another will follow in November asking men to consider giving 'an alternative Christmas gift'. In January 2016 the sperm bank will start shipping its first batches of sperm to clinics around the country, and this income will provide further opportunities for advertising, Witjens told The Guardian.