Utilitarian in this context implies that a decision is made by some people with power over other people without power with respect to the human dignity and worth of the latter.
Either all human beings have rights, or only some human beings have rights. Is there such a thing as a human being without human rights?
If all human beings have rights, then either all human beings have rights simply because they are human beings, because such rights are intrinsic in human nature, in the human essence, in the human being, or all human beings have rights because some other human beings say so. There is no other logical possiblity. If the Preamble of the Declaration is any guide, the wrongness of the utilitarian approach lies in the arrogant and false presumption that human wills determine human rights. Human nature does not change, but human wills do. There is no security for any rights at all based on a conceit of some human wills saying today that all humans have rights saying tomorrow that only some have rights. History is filled with the sordid misery of that ethos.
Cordially,
Are you contending that a blastocyst, for example, has rights? If so, is there any stage in the reproductive cycle where discrete cellular development is without rights?