Two recent IVF mix ups have occurred this year in Victoria, Australia, raising questions about the relevance of biological affinity in determining parenthood. In one case, a woman gave birth to a strangers’ embryo, of which the mistake wasn’t realised for almost two years after the child’s birth. In the second case, a woman gave birth to her own embryo instead of her partner’s. As to the former case, it is yet unknown what the genetic parents intend to do, or, for that matter, whether the birth parents wish to keep this child. In the meantime, a child exists, and a decision must be made as to which parents ought to keep the child. Ideally, either the genetic parents or the birth parents lay claim to the child, however, the situation may arise that neither or both the genetic and birth parents want the child. In such circumstances, we must ask, which parents should keep the child? This presentation will present an account of the reasons for and against each couple having the strongest claim, in law and ethics, to full parental responsibilities for the child.