The Immorality of In vitro Fertilization

John B. Shea, MD FRCP(C)

Biological Considerations

Procreation of a human being can be achieved either by sexual or by a-sexual means. Normally and morally, it occurs as the result of sexual intercourse in marriage. It can also be achieved by technical means, which may be sexual or a-sexual. Sexual reproduction  is achieved by the union of donated sperm with ova obtained by super-ovulation and needle aspiration with the help of diagnostic ultrasound. A-sexual reproduction is achieved by various types of cloning. These include pro-nuclear, mitochondrial, germ-line nuclear transfer, germ-line gene transfer, germ-line recombinant DNA manipulation and cloning involving the use of artificially constructed genetic materials produced by nano-technological methods. Yet another form of cloning involves splitting the embryo at the blastocyst stage, or by the process of spontaneous ‘regulation’ of one or two blastomeres, deliberately separated from the early embryo.

A human embryo comes into existence at the moment of conception. In sexual reproduction, this occurs when the oocyte is fertilized, a process that begins as soon as the sperm comes in contact with the oocyte membrane. In cloning, it occurs when a nucleus is transferred into an oocyte, when an embryo is split, when a blastomere separated from the early embryo, either deliberately or by chance, changes by a spontaneous process called ‘regulation’ into a zygote. It is important to realize that there is no such biological entity as a ‘pre-embryo’, and that it is scientifically and morally incorrect to label an embryo by such terms as ‘a fertilized ovum’, ‘a single cell’ or ‘a clump of cells.’ These euphemisms have been concocted for pragmatic reasons, in order to justify the use of chemical abortifacients, IVF, cloning, genetic engineering, and many other immoral practices.

Catholic Moral Teaching

All forms of IVF are prohibited by the Church’s teaching.1 In virtue of its apostolic teaching, the Church expounds the criteria for moral judgment in regard to the applications of scientific research and technology, especially in relation to human life and its beginnings. The transmission of human life has a special character that derives from the special nature of the human person. Its transmission is entrusted to a personal and conscious act, the bodily union of husband and wife in marriage, and as such, is subject to the all-holy laws of God. At its beginning, human life is sacred because it involves “the creative action of God”2 and it remains forever in a special relationship with the Creator who is its sole end.3

Reasons why human procreation must take place in marriage include:

  • By virtue of the personal dignity of parents and children, procreation must be the fruit and sign of the mutual self-giving of the spouses and of their fidelity.
  • The child has a right to be conceived, carried in the womb, brought into the world, and brought up within marriage.
  • By reason of their vocation, and social responsibilities, the parents contribute to the good of their children and the good of society.

Teaching on Heterologous IVF

Here, the child is conceived using sperm collected from a donor other than the husband. Heterologous IVF violates the unity of marriage, the dignity of the spouses, the vocation proper to parents, and the child’s right to be conceived from marriage. It deprives the child of his filial relationship to parents, can hinder his personal maturation, damage family relationships, and be a source of disorder and injustice in the whole of social life. For these reasons, Heterologous IVF is morally illicit.

Teaching on Homologous IVF

Here, conception is achieved using sperm collected from the husband. The Church teaches that there is an “inseparable connection, willed by God, and unable to be broken by man … between the two meanings of the conjugal act; the unitive meaning and the procreative meaning. The procreation is deprived of its major perfection when it is not desired as the fruit of the conjugal act.” Spouses mutually express their love in “the language of the body.”4 The conjugal act is inseparably both corporal and spiritual. Procreation is therefore linked to the union, not only biological, but also spiritual, of the parents. 5 In  light of the above it is clear that the Church teaches that homologous IVF is in itself illicit, even when the procedure is free of any compromise with the abortive practice of destroying embryos and with masturbation.

Distortion of Facts

Those who advocate the use of embryonic stem cells for therapeutic purposes have grossly distorted the facts in regard to the availability of those cells and their clinical promise. Four hundred thousand frozen embryos are said to exist in the U.S. that could provide potentially an unlimited number of stem cells. They are said to have the potential to cure numerous diseases. The truth is otherwise. A Rand Corporation survey has shown that only 2.8% (that is, 11 thousand) of those embryos have been designated for research. The study calculated that only about 275 stem cell lines could actually be developed from those embryos.7 Dr. Barry Behr of Stanford University states that the vast majority of frozen embryos are no good and that if we thawed 10,000 embryos, we would get 100 or so that are viable blastocysts.

The therapeutic benefit of these cells is purely speculative. To date, no clinical success resulting from their use has been recorded, and success it most unlikely because of the danger of tumor formation by the undifferentiated cells. Some have suggested that making clones of a patient would avoid tissue rejection. This may not work because the cloned cells contain foreign mitochondrial DNA from the oocyte used in producing the clone. Drugs used to prevent tissue rejection, which may have to be taken for a lifetime, carry a high risk of causing infections and are associated with a 5% increase in the incidence of cancer after a few years and an overall increase in cancer risk. Abnormalities found in cloned cells caused by epigenetic imprinting errors can also lead to tumor formation and are therefore a further possible hazard of embryonic stem cell therapy. The real probable use of embryonic stem cells is in the areas of genetic engineering and pharmacological research.


To love is to give. God has given human beings the gift of biological life and of life eternal, the ‘donum vitae.’ It is therefore a matter of justice as well as of charity, that we thank Him for that gift and in return, give Him our love and our obedience, and that we love our neighbor as ourselves. A human being is the only creature on earth made by God for his or her own sake, and must never be treated as a means to an end. An embryo is not a “doggie in the window” … and is not “for sale.” An embryo is not a ‘product’ or an ‘asset’ that can be accepted or rejected, bought or sold. An embryo may not be ‘returned to the maker’ by abortion. An embryo may not be used for experimental purposes, however laudable. It is reification of the human being that has led to IVF, genetic engineering and the phantasmagoric imaginings of the so-called ‘transhumanists’.

Even in deciding whether to use a legitimate treatment, the physician must weigh its potential benefits to the patient against its risks. Since IVF is never morally legitimate, such a risk/benefit analysis is irrelevant. One cannot make a legitimate moral claim that the procreation and acquisition of a human being is a true benefit if this person has been conceived by artificial means.

It should also be noted, that there are known risks to IVF, such as Ovarian Hyperstimulation Syndrome. This occurs in some women and one to two percent need to be  admitted to hospital. The symptoms include abdominal pain due to fluid accumulation, nausea, vomiting, and respiratory difficulties. On rare occasions, serious complications such as blood clots and renal or pulmonary disease occur, which may be life threatening. In the infant, the need for neurological therapy after birth is increased 3.7 times. There is an increase in the incidence of cerebral palsy in the newborn, and the incidence of suspected developmental delay is multiplied by a factor of four.6

It is also relevant to note that the availability of IVF harms marriage in other ways. In Australia, for example, the use of  IVF by unmarried women is not prohibited by law. There is also pressure in many countries to allow lesbians access to this procedure, and the use of surrogate mothers is now quite common.

Catholic physicians familiar with both spiritual and biological reality, must be in the vanguard in proclaiming and defending the splendor and sanctity of every person, especially of those who are frail and vulnerable at any time but particularly at the extremes of life.


  1. Donum vitae. Instruction in Bioethics. Congregation for the Doctrine of the Faith.
  2. Pope John XXIII, Encyclical, Mater et magistra 111 AAS 53 (1961) 447.
  3. Pastoral Constitution. Gaudium et spes. No. 24.
  4. Pope John Paul II, General Audience on January, 16, 1980, Inseguamentia di Giovanni Paolo II, 111, (1980), 148-152.
  5. Pope John Paul II, Discourse to those taking part in the 35th. General Assembly of the World Medical Association. Oct. 29, 1983, AAS 76 (1984) 393.
  6. B. Stromberg et al. “Neurological Sequelae in Children Born After In vitro Fertilization. A Population-Based Study.”  The Lancet. vol. 359, no. 9  305 (Feb. 2002) 461-465.
  7. Hoffman D.I. et al.  Cryopreserved Embryos in the United States and Their Availability for Research. Fertility and Sterility, 78 (5): 1063-1069.

Writing from Toronto, John B. Shea, MD, is a retired radiologist. He is a member of the Fellowship of Catholic Scholars, and of the editorial board of Catholic Insight  Magazine (Toronto), and a member of the Canadian Catholic Bioethics Institute.


© 2007 John B. Shea, MD



Last updated January 29, 2007 12:58