The predominant purpose of pre-implantation genetic diagnosis (PGD) is to select those embryos that are considered healthy or normal. This inevitably means that those that have a genetic abnormality are discarded. Foundational to how one responds to PGD will be their understanding of the personhood of the human embryo. Often, the ethical debate is approached from the assumption that human life at this stage of development is not a person and therefore can be disposed of if deemed unfit for implantation.
Further, PGD is often offered as an alternative to abortion. “Supporters of PGD see it as an opportunity to remove abnormal genes… without the ‘practical and ethical problems’ of experiencing the abortion of an affected child after traditional prenatal diagnosis.” Abortion may be ethically problematic, but discarding embryos is not.
This is ironic because much of the abortion debate has focused on the relevance or irrelevance of the location of the fetus in the mother’s womb. Abortion advocates oppose the killing of babies after birth, yet claim the woman has the right to determine what is done inside her body. Using PGD to determine whether to implant or discard a human embryo reverses the location of the human person in the process of growth and development.
To support using PGD to determine which embryos to discard on these grounds commits the same fallacy abortion commits by associating the personhood of the embryo or fetus with its physical location or development. I have posited before that the personhood of an individual does not rest upon their traits, capacities, or abilities. Therefore, it certainly does not rest upon their location and size. In fact, I would go so far as to affirm this statement: “Discarding an embryonic human because they do not have certain characteristics is discriminatory….” And as ethicist Scott Rae points out, “the underlying reasoning that justifies… testing is a crude form of utilitarianism, in which the ends justify the means, and in which results are more important than ethical principles.”Using PGD to discern if the embryo has a genetic disease, disability, or physical impairment with the intent to discard human life based upon these reasons is morally wrong. Human life is sacred irrespective of one’s capacities or disabling conditions.
 Brent Waters, From Human to Posthuman: Christian Theology and Technology in a Postmodern World (Aldershot: Ashgate, 2006), 378-79.
 Ibid., 379.
 Ibid., 379-80.
 Scott B. Rae, PhD., “Prenatal Genetic Testing, Abortion, and Beyond” in Genetic Ethics: Do the Ends Justify the Genes? eds. John F. Kilner et. al. (Carlisle, Cumbria, U.K.: Paternoster Press, 1997), 142-43.