By Andrew Dutney, Adelaide, Australia
Stem cell research is not in itself particularly controversial. Everyone is touched in some way by one or
more of the health crises that stem cell research hopes to address - spinal injury1, Parkinson's, diabetes,
heart disease and many more. The promise of new breakthroughs in the treatment of disease and injury
using stem cells inclines almost all commentators to support the endeavour. Of course there are several
important ethical issues involved that still need to be considered. - Is this development driven more
by the desire for profit than concern for healthcare? How far should biotechnology industries be allowed
to set the research agenda? Is Western culture no longer able to give people a sense of peace in facing the
realities of aging and mortality? But it is generally agreed that the potential benefits justify the
The most intense ethical controversy around stem cell research has focused on one matter - where the
stem cells are to be obtained. Children and adults have 'multipotent' stem cells that can be used in
research and in experimental treatments. But the most versatile, 'pluripotent' stem cells are to be
found in the human embryo at an early stage of its development. Adult stem cells can be helped to
differentiate into many different kinds of cells but, theoretically, embryonic stem cells could be
helped to differentiate into almost any kind of specialised cell. However, while adult stem cells can
be collected without harming the person, embryonic stem cells are collected from the embryo by
This is the focus of controversy in stem cell research - do the potential benefits justify destroying
human embryos? Christian commentators have presented a range of views.
Roman Catholic teaching affirms that from the moment of fertilisation2 the embryo's 'rights as a person
must be recognised, among which in the first place is the inviolable3 right of every innocent human being
to life'. Some Protestant commentators take the same position. In such a view, the deliberate destruction
of an embryo is tantamount4 to murder or, if some version of the principle of double effect is applied,
By contrast, in the public discussion prior to and following the introduction of the Research Involving
Human Embryos (Cth) Bill, in 2002, Anglican Archbishop Peter Carnley argued that the embryo should not
be regarded as a human being until after 14 days of development. This is roughly the stage at which it
develops the first signs of a primitive nervous system and also about the point at which the embryo would
implant in the mother's uterus5 in natural conception6. It also brings to an end the period of time during
which an embryo might split to produce identical twin embryos. This perspective has been conventional in
public policy at least since the time of the Warnock Report in the United Kingdom (1984), which
recommended that the cultivation of human embryos outside a woman's body should be limited to a
period of less than fourteen days. Legislation in the United Kingdom and Australia has consistently
adopted that restriction. In Carnley's view, then, 'conception' is a process that takes about fourteen
days. For him, the destruction of the embryo in research can be justified up until that time.
My own view is like Carnley's, but different in one important respect. In my view it is not so much the
developmental stage of the embryo that is crucial, but whether or not it has implanted in the woman's
uterus. I hold that the 'conception' of a human being cannot be said to have taken place until (and
unless) the woman becomes pregnant. In what follows I will provide a brief explanation of this position.
2. Fertilisation, implantation and conception
In natural conception several days may pass between the time when the woman's egg is fertilised and when
it implants7 in the wall of her uterus and she becomes pregnant. In 'in vitro' fertilisation (IVF) the
fertilised eggs are allowed to develop for some days before one or two of the healthiest embryos are
transferred to the woman's uterus in the hope that one might implant in due course and she become
The important point to note here is that there are two distinct stages. First, an egg is fertilised
by a sperm (either naturally or by IVF), creating an embryo. Second, the embryo implants in the
lining of the mother's uterus, having found its way to her uterus either naturally or by being
placed there in an embryo transfer procedure (ET) after IVF. It is to be emphasised that in IVF-ET
the clinician does not 'implant' the embryo in the mother's uterus, but 'transfers' it to her uterus
from its petri dish8. Once transferred to her uterus the embryo either implants or it does not. Whether
or not it implants depends on the condition of the woman's uterus and the condition of the embryo
(especially, its chromosomal 'normality').
Implantation is a crucial process and one which is largely beyond the control of reproductive technology.
It is something that happens in the interaction between the woman's body and the embryo. Clinicians
estimate that a majority of embryos do not implant - neither in IVF-ET nor in unassisted conception.
Indeed they have no prospect of implanting because of either their own morphology or because of the
receptivity of the woman's uterus.
According to recent South Australian statistics, approximately 3.5 ET procedures are required to
achieve one pregnancy. That is, since two embryos are generally included in each ET, approximately
seven embryos are used to achieve one pregnancy. And this high rate of embryos failing to implant is
considered by clinicians to be likely to compare favourably with the rate of failure in unassisted
conception. In IVF-ET the embryologist has the opportunity to select the embryos which appear to be
the best formed to be transferred; which ought to improve the implantation rate. In addition, the
cycle of treatment includes the administration of drugs to optimise the condition of the woman's
uterus and close monitoring of her cycle to ensure that the embryo transfer is conducted at the best
time to achieve a pregnancy.
So while it is quite true that every human being began life as an embryo, it is not the case that
every embryo is the beginning of a human being. Not even most embryos are the beginning of a human
being - not in assisted reproductive technology, and certainly not in nature. Whether they are
created naturally or through IVF, only a small minority of human embryos are in fact the beginning
of human beings. Not until the woman is pregnant can we be confident that an embryo (or at least
one of the embryos transferred in an IVF-ET procedure) is becoming a human being. And it is becoming
a human being precisely by implanting in the mother's uterus. In that process, and not before, a
human being is conceived.
Source: Stem Cell Research and Cloning: Contemporary Challenges to Our Humanity, ATF Press, Adelaide, 2005, pp. 95-98
1. spinal injury - Wirbelsäulenverletzung
2. fertilisation - Befruchtung
3. inviolable - unantastbar
4. tantamount - gleichbedeutend mit
5. uterus - Gebärmutter
6. conception - Empfängnis
7. to implant - sich einnisten
8. petri dish - Petrischale (chem.)
1. What is the difference between embryo stem cells and adult stem cells?
2. What benefits could stem cell research have for ill people?
3. Under which circumstances would Christians allow research on embryonic stem cells?
4. What is the author's view on whether an embryo is a living being or not?
5. The majority of embryos do not implant in a woman's uterus and so are 'destroyed'. When
do more embyos perish. in IVF or in unassisted/natural conception. Substantiate your findings.
6. Embryonic stem cell research could even result in cloning people which is commonly agreed as unethical.
What is your opinion on cloning living creatures?