This article will clarify a certain dimension of the debate over embryo adoption and lead to the conclusion that a woman who chooses to have an orphaned embryo implanted in her womb (heterologous embryo transfer, which we'll call HET), cannot be morally approved.

I have been a leader in the pro-life movement for over 30 years, and no one would more like to see all of the abandoned frozen embryos rescued. The nature of their in vitro conception, subsequent freezing and reduction to so-called "leftovers" constitutes a grave injustice.

Many people, motivated by real charity, look to embryo adoption as a way to save these frozen human beings whose precarious lives number in the tens of thousands. They argue that Vatican statements against surrogate motherhood are narrowly focused and even unclear. Moreover, since HET does not involve the exchange of sexual intercourse, namely it does not involve a formal act of adultery, they conclude that no moral laws are violated in embryo adoption.

Vatican statements, however, are not as open or equivocal as advocates of embryo adoption interpret them. Dignitas Personae (The Dignity of the Person), the instruction recently issued by the Congregation for the Doctrine of the Faith, directly addressed the fate of frozen embryos and concluded: "The proposal that these embryos could be put at the disposal of infertile couples as a treatment for fertility is not morally acceptable for the same reasons which make artificial heterologous procreation illicit as well as any form of surrogate motherhood; this practice would also lead to other problems of a medical, psychological and legal nature."

The document clearly regards embryo adoption as a form of heterologous procreation — namely a form of reproduction that involves an outside third party — already condemned in the 1987 Vatican document Donum Vitae (The Gift of Life). Moreover, while Donum Vitae explicitly condemned only one form of surrogate motherhood, the new document, Dignitas Personae, very clearly states that "any form of surrogate motherhood" is morally illicit. By definition and context, the new document recognizes embryo adoption as a form of surrogacy.

Advocates of embryo adoption argue, based on Humanae Vitae (The Regulation of Birth), that the Church is only concerned about the God-willed inseparable connection between the procreative and unitive meanings of the conjugal act. Since embryo adoption doesn't involve such acts, the marriage bond is not violated. This analysis is based on a very narrow, minimalist definition of procreation, as if sexual intercourse was the only single nuptial aspect of the marriage bond.

A strong argument exists that the Church believes procreation to be a more comprehensive and profound reality. Dignitas Personae describes embryo adoption as a kind of procreation when it condemns this practice as a form of "artificial heterologous procreation." This means that, while no acts of intercourse occur, the gestation of a baby is nonetheless part of the meaning of procreation — and procreation must remain within the bond of the marriage covenant.

Donum Vitae asks the very question: "Why must human procreation take place in marriage?" — and describes procreation as a prolonged and extended process.

The document teaches: "For human procreation has specific characteristics by virtue of the personal dignity of the parents and of the children: The procreation of a new person, whereby the man and the woman collaborate with the power of the Creator, must be a sign of the mutual self-giving of the spouses, of their hope and of their fidelity. The fidelity of the spouses ... involves reciprocal respect of their right to become a father and a mother only through each other."

The document immediately, in the very section focused on the meaning of procreation, describes procreation: "The child has a right to be conceived, carried in the womb, brought into the world and brought up within marriage: It is through the secure and recognized relationship to his own parents that the child can discover his own identity and achieve his own proper human development."

These are the "specific characteristics" of procreation. The document is not prohibiting the adoption of a child already born or prohibiting so-called artificial wombs or incubators when medically indicated. It is focused on the use of sexuality itself within marriage and does not identify procreation as limited to the conjugal act.

At stake in the debate over embryo adoption is the very meaning of the marriage bond and the connection between husband and a wife and fatherhood and motherhood. Many argue that embryo adoption is not adultery. However, the fact remains that when a woman has a thawed orphaned embryo transferred into her womb she is in fact procreating — namely becoming a mother — in relation to another man's child.

Is this justified only because she never exchanged a sex act with this man to produce this child? She has become a mother outside of that freely given gift of self to her spouse, which is the essence of the marriage bond. She has allowed her body to be used to gestate another man's baby. In marriage, spouses freely give of themselves — the total embodied word of the personal self is handed over. In a liturgy of nuptial embodied love, the man and the woman speak the total word of their masculine and feminine self donation. Marriage is a sexual/procreative friendship that involves the entire nuptial meaning of the body.

This nuptial meaning of the body, by definition, includes not simply the promise of spouses to engage in conjugal acts only with one another, but that one's reproductive organs — what constitutes the entire masculine and feminine word —is also inherent to their nuptial communion.

The wife has no right to use her reproductive powers outside the sphere of her marital commitment. The husband has no right to give her permission to do so. Her reproductive powers are constitutive of her nuptial word already handed over to her husband. Her status as wife is linked by natural law and the sacramental truth of her body to her motherhood. There's a direct moral, not simply biological, relation between the conjugal act and the womb.

This is why nuns and single woman may not permit their wombs to be used to gestate an orphaned embryo or an unborn baby whose mother is unable to carry him.

Many faithful theologians believe, in good conscience, that they may continue to argue in favor of HET, but it appears the Church is headed toward a definitive negative answer.

Frozen orphaned embryos bear the burden of the injustice of their in vitro conception. I do believe that the principle of double effect offers a resolution — albeit a sad one.

Frozen embryos are subjected to injustice. Thawing them is a reversal of the injustice — to free them from a condition contrary to their dignity. This is the directly chosen and directly willed good effect. The evil effect, their deaths, is not willed and not directly chosen. The principle of double effect can be exercised when one knows that the ontically evil effect will happen — not only when there's a possibility that it won't.

Ultimately, as Christians, we need to gird our loins and change this pro-death culture — a culture that would treat and even call any human being a "leftover."

Monica Migliorino Miller, Ph.D.,
is a professor of sacred theology at
Madonna University in Livonia, Michigan.