British people conceived using donated egg, sperm or embryos will be able to ask for identifying information about the donor when they reach the age of 18, following a law change that came into force on 1 April 2005. Fertility experts have welcomed the move towards openness, but fear that the legislation will worsen the current shortage of donors in the UK. It could also lead to an increase in the use of unregulated internet sperm agencies, and the number of couples travelling for treatment in other countries, they say.

Fertility clinics say that they have already noticed a decline in the numbers of people coming forward to donate gametes, since the announcement, made last January, that the rules on anonymity were to be changed. Speaking on the day the new law came into effect, health minister Stephen Ladyman said: 'We think it is right that donor-conceived people should be able to have information, should they want it, about their genetic origins and that is why we have changed the law on donor anonymity'. On the predicted shortage of donors, he said that 'we are working hard with the National Gamete Donation Trust (NGDT) to encourage more people to become donors and have launched an awareness campaign which aims to change public perceptions of donation'.

British agencies offering to collect and supply fresh, rather than frozen sperm do not have to be licensed by the Human Fertilisation and Embryology Authority (HFEA), so will not be covered by the new regulations. According to a report in the Daily Telegraph, internet company ManNotIncluded.com says that it will import sperm from countries where donors can donate anonymously and have it delivered to a woman's home. Founder John Gonzalez said that by using sperm sent from abroad in a 'constantly thawing state', ManNotIncluded will be able to supply anonymous samples directly to women in the UK. However, a spokesman for the HFEA warned that women using unregulated services could not be certain of the source, suitability and efficacy of the sperm they received.

Laura Witjens, chair of the NGDT, said evidence from countries that have already removed donor anonymity, such as Sweden, shows that it is no longer young students who donate sperm. After an initial fall in donor numbers, she said that the profile of donors changes: 'Instead of young single men who do not have children, it tends to be older men, who do have children and who see that what they are doing is creating a family, who come forward', she explained. But Allan Pacey, chair of the British Fertility Society, warned that 'there is now serious concern about the future of fertility treatments using donated gametes'.