The Catholic Church teaches that IVF is morally illicit without exception, even when the couple uses their own egg and sperm, and without super-ovulation of the mother or the creation of multiple embryos for implantation. Catholics and non-Catholics alike have struggled to understand this moral teaching and wonder how the Church can condemn a medical procedure aimed at bringing about new human lives.
The answers lies in even deeper reasons for this moral teaching which reach down into the very core of what it means to be husband and wife. The 1987 Instruction Donum Vitae (DV) by the Congregation for the Doctrine of the Faith contains the Church's most complete articulation to date of those reasons.
(1) First we must begin with marriage, the exclusive and permanent one-flesh union of a man and woman. Marital love, by its very nature, tends toward a two-fold fruition: toward the ever deeper, loving union of the spouses, and the unfolding of that love in the procreation of new human life.
The moral significance of these two dimensions - the procreative and the unitive dimensions of marital love - becomes most clearly manifest in marital sexual intercourse. In this context, it becomes easier to understand why the unitive and procreative dimensions of marital intercourse may never be intentionally separated.
Such was the core teaching of Paul VI's encyclical Humanae Vitae. Human beings cause themselves and others grave harm when they sever the "unbreakable connection" between the unitive and procreative dimensions of marital sexual intercourse.
Consequently, as explained in DV, it is morally wrong for married couples or anyone to attempt to generate human life outside of, or apart from, the act of marital sexual intercourse because to do so severs those dimensions: in IVF, procreation takes place in a Petri dish, apart from the unitive dimension of conjugal act.
(2) A second argument is based on considerations of the dignity of the child conceived by these means. DV argues that bringing a child into existence as a product of a technique is to render that child an object. Children brought into the world through IVF are arguably not generated, but manufactured. While the couple provides the 'materials' (ovum and sperm) for the creation of the child, it is a laboratory technician who brings about a new human life in a laboratory dish. The Church further teaches, that in light of this same human dignity, every human being possess a right to be "conceived and born within marriage and from marriage."
