Abstract
This study originated from events that occurred in 2014 in an Italian hospital, where the embryos of a couple, obtained by means of homologous insemination, were mistakenly implanted into the uterus of another woman who, along with her husband, underwent the same treatment. Faced with this serious adverse circumstance, that gives rise to ethical and legal issues, the authors conducted a comparative examination of how to consider the division of maternity (between biological mother and uterine mother) and the related division of paternity (between genetic father and legal father, husband or partner of the gestational mother). Some preliminary observations are made concerning parenthood and filiation within the context of currently applicable Italian law. The following is a detailed analysis of the arguments in favour of the parental figures involved (gestational mother/genetic mother).