Abstract I The expression "sowing, to breed afterwards" is used as a way of promoting one of the private centres for reproductive medicine in Portugal. Through the analysis of the criteria that justify the establishing of boundaries in the delimitation of the legitimate beneficiaries of the MAP in Portugal and the adequate profile of egg donors and semen donors, this paper seeks to demonstrate that doctors and jurists resemble the responsible arbitrators in the scrutiny  of "good" and "bad" seeds, whose declared main goal is to assist nature in the  obtainment  of  a good sow. Resorting to an element of naturalistic and genetic  appearance (the seed) strengthens the image of human reproduction as a process that is essentially natural and bio-genetic which aims to "create", that is, to generate and promote  biological procreation , but also to raise a child, articulating biological, genetic, affection, social and moral dimensions amid  the scope of human reproduction. It follows that the recent emphasis on the use of alleged biological and natural elements in the government of   the patient appropriate for the MAP techniques is associated to the moralization of maternity, genetization of paternity and to the (re)construction of a positive image of technology and medicine, which might restrain the possibility of citizens questioning medical and technical interventions in this field.