A few treatments using donated gametes are paid for by the NHS, with funding weighted towards straight couples, the figures show. Some 40% of all funding for IVF comes from the NHS; but only 18% of donor gamete IVF and 15% of Donor Insemination (DI) are funded by the NHS.

Published to coincide with National Fertility Awareness Week and the launch of the National Sperm Bank at Birmingham Women’s Hospital today, the report also includes clinics’ responses to a donation survey conducted by the HFEA late last year.

While the number of men registering as a sperm donor has increased gradually since 2005, 2013 saw a slight dip in new registrations. In 2011, 541 new sperm donors were registered, and this rose to 631 in 2012, when the HFEA introduced new donations policies and changed the rules on anonymity. Last year 586 donors registered.

The proportion of donor sperm coming from abroad, primarily from the US and Denmark, is increasing year on year, partly because the time and resources needed to recruit UK donors can sometimes make importation more viable, suggests the report.

The data show that the number of young people registering as sperm donors has risen, with almost a quarter of newly registered donors in 2013 aged under 25. Most of that increase was accounted for by donors in the 22-25-year age bracket, with the proportion of the very youngest donors remaining largely constant. Most sperm donors are 26 or older. A quarter were over 40.

The number of women registering as non-patient egg donors has risen every year since 2006, rising from 815 in 2011 to 1,103 in 2013. Clinics have also noticed an increase in both expressions of interest and actual donations since 2012.

As with sperm donors, around a quarter of newly registering egg donors were under 25 years of age, while half were over 30. Since 2012, the proportion of donors aged under 25 has risen from 12% to 24% since 2011.

Egg sharers are women who donate eggs and also have treatment themselves, usually in return for a reduced cost of treatment. After a peak in 2011, when 708 women registered to egg share, numbers have dropped since, with 533 women sharing in 2013.

Over 80% of egg sharers were aged between 26 and 35, reflecting the typical age of motherhood in the UK. Of the sharers who registered in 2013, a quarter already had children.

Laura Witjens, Chief Executive of the National Gamete Donor Trust, which runs the National Sperm Bank, added: “When the rules on anonymity were changed it was widely anticipated there would be an enormous decline in the number of donors coming forward.

“To see an increase in excess of 100% for both egg and sperm donors in the ten years following shows that the right decision was made, and importantly, that clinics have positively improved their recruitment practices.”

But she warned that supply is not meeting demand that the UK remained overly reliant on imported sperm or egg-sharing.

“For many clinics this is the easiest way, but in the long run this isn’t in the best interests for patients and their offspring. We should therefore continue to work on improving donor care and recruitment so that all patients have equal access to UK donors,” she said.