The number of men - especially students - volunteering as potential sperm donors has fallen sharply since 2000, a study has found. Researchers at the Newcastle Fertility Centre say the fall is almost certainly linked to scrapping the right of donors to remain anonymous. They say urgent action is needed to attract more volunteers, particularly among older men who may have partners. The Newcastle team examined details on over 1,100 men who applied to be potential donors between 1994 and 2003. Nearly nine out of 10 were aged under 36, more than half were students without a partner, 85% were unmarried and over three-quarters had no children. Nearly a third had opted out during the process, and almost two-thirds were rejected, most because their sperm was not of sufficient quality. At the end of the recruitment and testing process, just 3.63% were accepted as suitable donors. Crucially, just 25 potential donors came forward in 2003, compared with 175 in 1993. The sharpest fall occurred from 2000 onwards. From 1999, the numbers who changed their mind during the application and testing process also rose. The acceptability rate of donors also declined over the study period because of the introduction of stringent criteria aimed at improving standards of recruitment. Reuters