Polygenic Embryo Screening: Following the Logic of IVF

By: Christopher O. Tollefsen, originally published November 19, 2024, The Public Discourse

Even the most extensive attempt to shape “what we will get” will always fail to eliminate the contingency, particularity, and irreducibility of the person, whose concrete individuality will likewise always transcend whatever power we attempt to exercise over it.

In April of this year, Harvard Medical School researchers released the results of a survey they had conducted about polygenic embryo screening (PES). Still in its infancy, this emerging technology, performed on embryos created by in vitro fertilization (IVF), aspires to identify the probability that an embryonic human being will develop unwanted health conditions or traits arising from more than one gene.

A report from the Medical School about the survey notes the risks and limitations of PES: while some for-profit companies are now offering risk scores for certain diseases—including heart disease, diabetes, and depression—the technology is far from infallible. Nevertheless, a majority of respondents to the survey were positive about the possible uses of PES to screen for disease, and a third of respondents even supported the use of PES to identify desirable physical or behavioral traits. A similar number also indicated that they would consider using IVF to screen for or against desirable traits.

We are still a ways away from the specter of genetic screening, much less engineering, for the “perfect baby.” But we are likewise quite far down the road from the original impetus for IVF, the promise to married couples suffering from infertility that they could have a child of their own. For even quite early in the history of IVF, that technology was implicated in the production of surplus embryos which then would be graded, so that only the “best” would be implanted and the rest discarded or frozen. The practice of IVF similarly moved to the use of donor gametes, resulting in children biologically unrelated to one or more of the “social” parents, and to the use of gestational surrogates.

Intuitively, then, we should perhaps not be surprised that the road ahead will likely move further toward a future in which human beings in their earliest stages are treated like products to be created at will.

But the connection between where IVF began, what IVF is, and where it is going is more than just a matter of intuition. It is a matter of logic.  To see this, we should look at the argument made in one of the most perceptive, but insufficiently appreciated, treatments of the morality of IVF, the 1987 “Instruction” of the Congregation for the Doctrine of the Faith, Donum Vitae, “Instruction on Respect for Human Life.”

A wide-ranging treatment of bioethical issues at the beginning of human life—including research and experimentation on human embryos, surrogacy, and the use of assisted reproductive technologies—Donum Vitae notes the morally objectionable nature of the destruction or permanent cryopreservation of surplus human embryos and of the severing of marital fidelity that takes place in the use of donor gametes. But the “Instruction” also makes clear that its authors are deeply sympathetic to those couples struggling with infertility. Such couples have “legitimate aspirations” and find hope in IVF “when there is no other way of overcoming the sterility which is a source of [their] suffering.” So perhaps a pure case of IVF could be constructed, one which would involve no surplus embryos, no surrogacy, and no use of gametes from outside the marriage. Separated from these accidental features of common IVF practice, IVF could then be “judged in itself” to see whether it might indeed be morally permissible within the confines of marriage.

In answering this question, the “Instruction” makes an argument that has not, I believe, been anything like sufficiently appreciated. Yet it is an argument that casts a bright light on the logic of IVF in such a way as to indicate that neither the immediately subsequent abuses—again, creation of surplus embryos, embryo cryopreservation and destruction, donor gametes, surrogacy—nor the inertia towards designer babies, are entirely accidental to IVF. Rather, as we will see, they flow directly from the nature of the act itself.

Considering only the purest case of IVF, the “Instruction” argues:

Homologous IVF . . . is brought about outside the bodies of the couple through actions of third parties whose competence and technical activity determine the success of the procedure. Such fertilization entrusts the life and identity of the embryo into the power of doctors and biologists and establishes the domination of technology over the origin and destiny of the human person. Such a relationship of domination is in itself contrary to the dignity and equality that must be common to parents and children. 

The key claims here are that IVF places the life and identity of the human person in the hands of a third party—the physician and those working with him—and that in so doing, IVF establishes a relationship of domination that is contrary to the dignity and equality of parents and children. 

What does all this mean?

The central meaning is that in IVF, children are made, and made in the manner of a thing: at the will and desire of another. In IVF, parents and doctors desire a child. So they work together to collect biological material, sperm and oocyte, and then exercise technical skill in order to cause a child to come into being out of that initial biological material. Their control of the child’s origin extends to the moment of the child’s creation: we shall do this now. And it extends to the identity of the child: we shall do this with these gametes, the result of which will be a biologically different person than if we had done it with those gametes. We shall bring all our skills and techniques to bear on the material at hand with the purpose of mastering it, so that this time, here and now, a new human being will come into existence.

The attitude just described mirrors what is involved in the material creation of any other object: the fabricating of a desk, a car, or a house. But in all such cases, the attempt to master a set of materials in order to cause it to become the entity that we desire, is for us to establish our domination over and superiority to the materials under our control. And this relation is inevitably a relation that, while appropriate as between human persons and the material world (though, even there, abuse is possible), is utterly inappropriate as between human persons and other human persons. For it is a relationship incompatible with the equality of those persons: it is the relationship appropriate between a person and a thing.

So the objection of Donum Vitae to the pure case of IVF is that even in that pure case, the willingness of the parents and the doctors together subjects the child, in his or her coming into being, as much as possible to the will of his creators.

The truth of Donum Vitae’s account is given credence by the very phenomena that the “Instruction” sets aside in considering the pure case. For when we seek to master materials and subject them to our will but fail, what do we do? We discard them and try again. Hence the grading and elimination of “defective” embryos. What if our material is in some way the source of the problem? Then we seek better material. Hence the use of donor gametes. And in the drive to instrumentalize the coming into existence of a child, everything seems like a tool, even the mother and her womb. If a better tool is available, then surrogacy will seem entirely reasonable.

But why not raise our aspirations even higher? Why not seek to eliminate not only embryos known to be “defective,” but also those regarding whom we have some reason, via polygenic embryo screening, to think that they might be? And why rest content with screening for life-threatening conditions, or profound disabilities, when we can screen as well for possible heart disease, diabetes, or depression?

From there it is but a short step to screening for positively desired traits. For who makes a desk, a car, or a house aspiring only to an absence of obvious flaws? We desire our creative mastery over material nature to be as complete as possible, to conform maximally to what we desire out of that material nature. If we have the money, we seek a finely crafted desk, a sports car, or a mansion.

So the logic of making, of seeking to make “competence and technical activity determine the success of the procedure,” moves in precisely the direction that polygenic embryo screening now suggests, toward the creation of the perfect baby, at least, for those with the money and other resources to order one up.

But children, it bears saying despite the obviousness of the claim, are neither desks, nor cars, nor houses: they are not things at all. And the conditionality of desire that we reserve for things, discarding when they are not up to standard, improving according to our desires, is incompatible with the unconditionality of love that should accompany parenthood.

That unconditionality is unquestionably risky. For children, conceived (or adopted) in hope, but always also in deep ignorance of what the future will bring, come into our lives unbidden in their particularity. Even the most extensive attempt to shape “what we will get” will always fail to eliminate the contingency, particularity, and irreducibility of the person, whose concrete individuality will likewise always transcend whatever power we attempt to exercise over it.

What attitude should we have toward that unbidden-ness, that particularity, that irreducibility? I have mentioned unconditional love, love not predicated on anything that our children might accomplish or any attribute that they might possess. And I have mentioned hope, which surely includes the hope that our children will love us as we love them, unconditionally and completely. We should add gratitude, for however we come to have children, their existence in our lives is never something that we deserve, and it is always a gift.

And finally, in recognition of the source of that gift, and of our own radical insufficiency for bringing persons into the world by our own agency, we must have piety, a piety that acknowledges that we are only cooperators with God, the Lord of Life, who is present personally and individually in the coming into being of each individual person through a unique act of creation.

Such a form of piety requires a radical openness to the gift of children being given to us as God sees fit. And thus for many, and perhaps all, that piety will at some point be accompanied by suffering, whether in the having, or the not having, of children. Some of that suffering is properly within the province of medicine to address, and Naprotechnology, for example, has made great strides in promoting women’s reproductive health.

But the making of persons goes beyond what medicine, and marriage, are called to pursue: an approach to procreation that fully respects the “dignity and equality that must be common to parents and children.”

Christopher Tollefsen is Professor of Philosophy at the University of South Carolina, and an author. He is a Visiting Fellow with the deNicola Center for Ethics and Culture at the University of Notre Dame.