The ethics of stem cells
Margaret Somerville - National Post - Friday August 20, 2004

Human embryo stem cell research is the debate that won't go away. In Canada, despite being dealt with in the recently enacted Canadian Assisted Human Reproduction Act, it is still a focus of heated disagreement. It's become an issue in the U.S. presidential campaign. It is the subject of a current issue of the prestigious British medical journal The Lancet, the first ever issue of that publication devoted to one topic. And this month, Britain's Human Embryology and Fertility Authority approved the cloning of an embryo for purposes of harvesting its stem cells -- an unprecedented decision that generated news around the world. What is all the fuss about?

Human embryos have been created in the laboratory to treat infertility since the birth of Louise Brown, the first "test-tube baby," in 1978. So the creation of embryonic human life in vitro isn't new. What is new is the creation of embryonic human life with the intention of harvesting stem cells to make therapeutic products for the rest of us. As always in the field of bioethics, intention matters.

Until the recent advent of cloning technology, human life could be created only through the union of an ovum and sperm -- that is, through sexual reproduction. Through cloning, however, embryos can be created asexually. One method is by implanting a donor's DNA-encoded cell nucleus into an extracted female ovum. This process -- known as somatic cell nuclear transfer (SCNT), or the "Dolly technique" -- produces an embryo that is a genetic match for the DNA donor.

SCNT is called "therapeutic cloning" when the intention is to create days-old embryos from which stem cells can be harvested to make therapeutic products. Removing its stem cells kills the embryo.

Stem cells are the subject of scientific research because they have the potential to evolve into many different cell types -- including medically useful tissue such as liver or nerve. It is hoped that tissue grown from stem cells might one day be used to treat horrible diseases such as Parkinsons, Alzheimers, multiple sclerosis, cancer and diabetes, or to repair damaged spinal cords and other critical body parts.

While stem cells can be harvested from any embryo, cloning is seen as a key step in the process because it permits physicians to avoid the problem of tissue and organ rejection by ensuring that the stem cells bear the genetic signature of the treated patient -- who would also be the DNA donor.

In "reproductive cloning," the same process of SCNT is used -- but this time, with the intention of producing a child. Almost everyone agrees that reproductive cloning should be prohibited. On the other hand, they disagree sharply on whether therapeutic cloning should also be prohibited.

Under Canada's Assisted Human Reproduction Act, so-called "spare" embryos left over from in vitro fertilization (IVF) can be used for research, including stem cell research, if that is the only way the research can be undertaken. But those embryos do not provide a genetic match for people who might need treatments. And they must not themselves be cloned -- which is possible by separating the cells at a very early point in the embryo's development -- because all cloning, therapeutic or otherwise, is prohibited. Creating embryos for any purpose other than IVF is also prohibited.

Some Canadian observers, scientists especially, are advocating that these restrictions on embryo stem cell research be relaxed -- in particular, that therapeutic cloning be permitted. The same debate is taking place in the United States, where the Republicans and Democrats have each made the stem cell issue a hot subject in the current presidential election campaign. In August, 2001, the Bush administration banned all cloning and any use of additional human embryos as a source of stem cells in institutions receiving federal funds; a Kerry administration, it seems, would liberalize these policies.

To understand why there is so much disagreement about how to resolve the ethical issues raised by embryo stem cells and cloning, we need first to understand the two different basic approaches to ethical analysis: Principle-based ethical analysis and utilitarian or situational-based ethical analysis.

In principle-based ethics analysis, the first question is whether something is inherently wrong. If it is -- for instance, creating a human embryo in order to use it as a product by harvesting its stem cells, killing it in the process -- it must not be done no matter how much good could result.

In contrast, utilitarian-based ethics analysis posits that what is right and wrong depends on whether the good sought outweighs the risks and harms. Consequently, those who use this approach to justify human embryo stem cell research start by presenting the long list of potential benefits, such as curing cancer, repairing severed spinal cords and so forth.

So if we are trying to create a public policy consensus on the subject, we must first answer this question: "Is human embryo stem cell research inherently wrong?"

Usually, that question is addressed only in regard to the treatment of human embryos once they exist. But even putting aside the question of whether it is acceptable to destroy an embryo to help treat another human being, the introduction of cloning technologies and stem-cell therapies raises separate ethical questions about what limits should be respected in regard to the transmission of human life.

We are the first humans who've ever faced this issue, because it arises solely from the possibilities opened up by reprogenetic technologies.

People who object to therapeutic cloning for embryo stem cell research typically object on the grounds that it is inherently wrong (a) to transmit human life with the intention of killing it; (b) to do so for the purpose of using the resulting embryo as a means toward providing therapeutic products; and (c) to transmit human life other than by sexual reproduction.

According to such a view, creating an embryo with the intention of helping an infertile couple have a baby can be consistent with respect for the transmission of human life. And using "spare" embryos left over from IVF as a source of stem cells is a separate issue, one whose resolution depends on what respect is owed an existing embryo. (A strict view would hold that even the use of IVF embryos for stem cell research should be rejected, as it contravenes the respect we owe to the earliest form of human life.) But in any case, human embryo stem cell research other than on such "spare" IVF embryos should be prohibited.

Those who want to allow embryonic stem cell research do not confront the hard ethical questions related to respect for the transmission of human life, and go straight to the utilitarian analysis of the use of embryos. Moreover, they commonly avoid the use of the word "embryo" and, for instance, characterize embryos created through therapeutic cloning as just a "clump of cells."

Likewise, they refer to "spare" IVF embryos as "potential human life" -- despite the fact they are, given the right conditions, human life with the potential to go on living for years and years, just like all of us.

The strongest argument for using "spare" IVF embryos is that nothing is lost by their use. That is, they will die anyway when discarded by the clinic. But the same logic applies (broadly) to dying people. And yet, all of us would be appalled at the idea of terminating their lives so we could harvest their tissues or organs in order to save others. We maintain respect for their lives and do not use them simply as products.

This last point hints at a broader reason to be very careful about how we treat embryos -- the precedents we could set that would be open to application to the rest of us.
The Assisted Human Reproduction Act reflects the view that to create embryos other than by sexual reproduction and other than to help people have children is inherently wrong, and that human embryos no longer required for IVF procedures may only be used when such use is necessary for research.

While some observers disagree with any use of embryos for scientific research, the overall position taken by the Assisted Human Reproduction Act seeks to maintain respect for human life and its transmission. We must ensure that such respect endures. And so Parliament should not change the Act to allow therapeutic cloning or the creation of embryos other than for IVF treatment for infertility.

Margaret Somerville is founding director of the McGill Centre for Medicine, Ethics and Law. She is author of The Ethical Canary: Science, Society, and the Human Spirit.

Reprinted with permission from Margaret Sommerville