 UNESCO’s Universal Declaration on the Human Genome and Human Rights (1997) was the first international instrument to condemn human reproductive cloning as a practice against human dignity. Article 11 of this Declaration states: “Practices which are contrary to human dignity, such as reproductive cloning of human beings, shall not be permitted…” This position is shared by the World Health Organization, the European Parliament and several other international instruments. Critics have pointed out that the reference to human dignity is problematic as it is rarely specified how human dignity is to be understood, whose dignity is at stake, and how dignity is relevant to the ethics of cloning (Harris 2004, Ch.2, Birnbacher 2005, McDougall 2008,). Some commentators state that it is the copying of a genome which violates human dignity (Kass 1998); others have pointed out that this interpretation could be experienced as an offence to genetically identical twins, and that we typically do not regard twins as a threat to human dignity (although some societies in the past did), nor do we prevent twins from coming into existence. On the contrary, IVF, which involves an increased ‘risk’ of having twins, is a widely accepted fertility treatment.