This article explores the definitions of surrogacy within an international perspective. The definitions that appear in the debates and laws belong to four frameworks. The first describes the subrogation of motherhood as a medical technique: many laws and law proposals admit surrogacy only in this form. The second describes it as a gift; many countries only acknowledge "altruistic" surrogacy in their laws. The third describes it as a "job"; however, this model, advocated for also by social scientists, is not legal in any country of the world. The fourth is the most adequate: subrogation of motherhood essentially described as a judicial institution which generates a market in filiation. Within this framework, women agree to giving up their new-born children in contracts/agreements before the pregnancy; this framework, which is adopted in some countries, presents a slippery slope towards the can-cellation of any legal relationship between mother and child.