author proposes, from the perspective of the Scientific Ethics, to assimilate anencephalic fetuses to non-human fetuses because they have a large deficiency of the brain that is the organ for human specificity. This proposal comes after considering arguments and facts from ontogeny, phylogeny, from the situation of loss of the brain in the adult life and from the organic specificity of the human condition given by the brain. If anencephalic fetuses are not human, the interruption of their pregnancy cannot be considered as abortion, regardless the pregnancy stage.