Daily Mail (UK) 18 Sep 2011
A British sperm donor has fathered 17 families, raising the risk of the offspring meeting and unwittingly having an incestuous relationship. The breach of the 10-family limit set by the Human Fertility and Embryology Authority came to light after research by a campaigning group. It also emerged that another man has created 12 families and three others have created 11. The HFEA also admitted it does not know how often its rules have been breached. Joseph Quintavalle, of Comment on Reproductive Ethics, the group which discovered the failings, told the Sunday Times: ‘There is a real danger in a small country like the UK for donor-conceived children to meet up unknowingly with half-siblings.
…..Experts believe that such children could suffer psychological trauma if they subsequently discover they have a very large number of siblings.