 In the case of sperm, the physical risks of donating are negligible, but concerns have been raised about psychosocial risks, especially if one man is permitted to generate numerous offspring. What happens, for example, if a single sperm donor produces hundreds of children and a significant proportion of those contact him years later? That could have a significant impact on the man’s life (and on the welfare of the children, discussed below). One way of containing this risk would be to limit donor offspring numbers; another would be to allow donor anonymity, although that may be objectionable on other grounds (see our earlier discussions of donor anonymity and donor offspring limits).