An embryo has no rights. Rights do not pertain to a potential, only to an actual being. A child cannot acquire any rights until it is born. The living take precedence over the not-yet-living (or the unborn).
Abortion is a moral right—which should be left to the sole discretion of the woman involved; morally, nothing other than her wish in the matter is to be considered. Who can conceivably have the right to dictate to her what disposition she is to make of the functions of her own body?
Never mind the vicious nonsense of claiming that an embryo has a “right to life.” A piece of protoplasm has no rights—and no life in the human sense of the term. One may argue about the later stages of a pregnancy, but the essential issue concerns only the first three months. To equate a potential with an actual, is vicious; to advocate the sacrifice of the latter to the former, is unspeakable. . . . Observe that by ascribing rights to the unborn, i.e., the nonliving, the anti-abortionists obliterate the rights of the living: the right of young people to set the course of their own lives. The task of raising a child is a tremendous, lifelong responsibility, which no one should undertake unwittingly or unwillingly. Procreation is not a duty: human beings are not stock-farm animals. For conscientious persons, an unwanted pregnancy is a disaster; to oppose its termination is to advocate sacrifice, not for the sake of anyone’s benefit, but for the sake of misery qua misery, for the sake of forbidding happiness and fulfillment to living human beings.

Ayn Rand

http://aynrandlexicon.com/lexicon/abortion.html