Submission on the Use of Preimplantation Genetic Diagnosis - Saviour Siblings

Staff of The Nathaniel Centre - July 2008
Issue 26, November 2008

A Summary of Key Points from Submission to Advisory Committee on Assisted Reproductive Technology [ACART] on Guidelines for Preimplantation Genetic Diagnosis (PGD) with Human Leukocyte Antigen (HLA) Tissue Typing (Saviour Siblings)


In debates about the use of human assisted reproductive technology Catholic-Christians share a common starting point with all New Zealanders; a holistic concern for the health and well-being of persons and society as a whole. We also share in common with others a belief that the principle of reproductive liberty does not confer a right to unfettered choice or access but signals the importance of the interests involved and the respect owed. The present discussion on preimplantation genetic diagnosis (PGD) with human leukocyte antigen testing (HLA tissue typing) once again concerns the precise nature of the limits to personal reproductive choice.

Regarding our views on PGD we reiterate what we have written on previous occasions: PGD inevitably involves the deliberate creation of extra embryos that will never be implanted. On this matter, Catholic teaching states that the fruit of human generation, from the first moment of existence, demands the unconditional respect that is morally due to the human being in his or her bodily and spiritual totality. The discarding of embryos for any reason is unacceptable.

We hold that all embryos have equal moral status and human dignity. While this is rightly regarded as an extension of Catholic beliefs regarding the status of the embryo, we know that many other people concur with this belief, including those who might not recognise that the moral status of an embryo was equivalent to that of a person. This stance rules out discriminating against embryos on the basis of health or disability.

A Catholic understanding of, and commitment to, the dignity of human life holds that the only legitimate intervention on an embryo arises in situations where it "respects the life and integrity of the embryo and is directed towards its safeguarding or healing as an individual."

Summary of Key Arguments

Catholic teaching emphasises that there is a reasonable dominion over nature that humans are entitled to exercise. Medical science and technology are valuable resources when placed at the service of human kind and when they promote the common good. Our arguments in this submission are not about the morality of technology per se. Rather, our concern relates to the protection of human dignity and wellbeing in the light of risks posed by the application of biomedical techniques at the beginning of life; in particular our ability to exert ever greater control over the sorts of children that we have through the expanding use of PGD.

Catholic teaching about [in vitro fertilisation] IVF and PGD reflects the fact that, in our choices about the means we use to have children, there are a number of important human values at stake that are integral to human well-being. In what we say, and through the meanings conveyed by our actions, we must uphold the fact that our children are persons with a right to be loved for no other reason than who they are.

We are particularly concerned about the robustness of the ethical debate surrounding the use of assisted human reproductive technologies. There is a distinct lack of transparency and consistency in regard to the ethical framework that seems to be behind the revision of the Guidelines for the use of PGD with HLA tissue typing. At other times we detect a narrow utilitarian approach that leaves deeper ethical considerations unaddressed.

PGD with HLA tissue typing creates an alternative "opening scene" for the story of a new life that is about to unfold, one in which, arguably, the main intention for having another child is utilitarian. The child is first of all seen as a means to an end even if, subsequently, he or she is seen and treated as loveable in their own right. The context surrounding such a birth is undoubtedly different from that of a child who is wanted only for his or her own sake and for no other reason. Consequently, the conception of a saviour child brings about a whole new relational dynamic within a family.

Just as importantly, at the societal level, by introducing a conditional element into our thinking about children, and by facilitating ever greater amounts of adult control over children, this technology arguably pushes us further along the continuum that makes it easier to see – and treat - children more and more as the products of adult desires.

The fact that the negative individual and societal consequences of the application of assisted reproductive technologies are "far from obvious", logically constitutes a strong reason not to proceed with the lifting of restrictions surrounding the use of HLA tissue typing. We are concerned that in many people's minds a lack of evidence of negative consequences is seen as a reason to proceed.

We remain opposed to all forms of PGD. However, mindful of the fact that current regulations in New Zealand already allow for the use of PGD in certain circumstances, and while not condoning either IVF, embryo selection or the destruction of embryos, our comments on the proposed guidelines are made with the intention of limiting the harm. It is our firmly held view that current restrictions on the use of PGD not be further relaxed in any way.

In what follows we will comment on the two key issues raised by the proposed new guidelines: (i) whether or not the use of HLA tissue typing should be used only to benefit a genetic sibling and (ii) the policy extension to allow testing of embryos for tissue typing for a non-genetic condition.

Specific Comments on the Proposed Guidelines

1. Should PGD with HLA Tissue Typing be used only to benefit a Genetic Sibling?

We submit that the use of PGD with HLA tissue typing should not be expanded to include its use for the benefit of close relatives for the following reasons:

  1. We do not see that there are adequate clinical reasons to support changing the guidelines that restrict the use of PGD with HLA tissue typing to benefit a sibling. In the case of a parent, the reality is that the chances of creating a child who is an HLA match are "extremely low", and except in very rare cases, a child will only match half of each parent's tissue type exactly. It is also our understanding that the chances of a match are equally low, if not lower, in the case of cousins.
  2. Where the chances of a match are extremely low, the practice of HLA tissue typing will only lead to greater numbers of embryos being discarded.

In our opinion the establishment of a New Zealand public umbilical cord blood bank would constitute a more constructive and pragmatic response to this question.

2. Should HLA Tissue Typing be Restricted to Situations Where the Disease is Genetic?

We submit that New Zealand policy on PGD with HLA tissue typing should continue to restrict the use of this technology to situations where the affected child suffers from a familial single gene disorder or a familial sex-linked disorder and the embryo is also at risk of being affected for the following reasons:

  1. Those who conclude that there is no valid moral distinction between using HLA tissue typing in the presence or absence of a genetic risk rely on an inadequate description of the moral action involved. The two types of action are radically different. In situations where PGD is performed for the sole purpose of giving birth to a healthy or disease-free baby, what happens is accurately and adequately described as an act of 'negative selection'; a choice to avoid a specific condition. Therefore, the conception of a saviour child represents an additional new rationale for this application, one which drastically changes the original objectives for using PGD.
  2. In cases where a future saviour child is at risk of inheriting the disorder because it is genetic in origin, we can now say that the original act of 'negative selection' takes on an additional motive; the desire to have a tissue matching child is supervened on the desire that the child-to-be, be free from this or that particular genetic condition. Such an act is no longer 'simply' an act of negative selection; nevertheless, it still retains its connection with the original objectives of PGD even while it introduces the additional element of 'positive selection' for certain traits. However, the conception of a saviour child in circumstances where the disease or disorder is not genetic leads us to a very different description of the act. What is otherwise an additional motive for using PGD becomes the sole motive. Now the use of PGD is more adequately described purely and simply as an act of 'positive selection'. HLA tissue typing for non-genetic diseases is quite another type of action and must, therefore, be judged on a different basis from its application in cases where the disease is genetic in origin.
  3. Approving the use of HLA tissue typing in cases where the disorder is not genetic would set a dangerous precedent for "positive selection". What might on the surface seem to be a small step crosses a significant ethical threshold which opens the way for further unlimited and highly undesirable applications of reproductive technologies.
  4. Without an ethical framework that sets out a rationale for limiting future uses of this technology based on a holistic understanding of the human person, we are left vulnerable in the face of pressures to use PGD in other ways that will undermine human dignity.


We do not question the nobility of seeking to cure horrible diseases. In fact, the Catholic healthcare tradition defends and promotes this. What is in question, ethically speaking, is the way in which the cures are sought. There is much wisdom in the idea that it is what we do at the very beginnings of life that sets the stage for our life long attitudes to our children. Personal experience and an awareness of both culture and history have surely taught us that there is a connection between the motives parents have for conceiving a child and the nature of the relationship they have with them, as well as the way in which children are viewed and treated within a culture or society.

The use of HLA tissue typing in any circumstance is out of step with a Catholic understanding of the dignity of human procreation and the dignity of persons. However, given the current circumstances in which we find ourselves, and for the reasons outlined above, we argue in the strongest terms possible that the Guidelines remain as they are. In other words, we submit that the revised guidelines continue to restrict the use of PGD with HLA tissue typing to situations where the disease is genetic and, furthermore, that they continue to restrict its use to benefit only genetic siblings.

Staff of The Nathaniel Centre

July 2008