Several scientists, associated with members of the medical profession, want to do experiments with early human embryos produced by fertilization outside the body (in vitro fertilization, or IVF).
They have used arguments unacceptable to any scientist in trying to convince the public that these early embryos are not young human beings at all. They also claim that their investigations will contribute importantly to knowledge of human reproduction, and to the prevention of infertility, miscarriage and congenital handicap. This claim is false.
Such experimentation will not significantly advance the basic science of reproductive physiology, and it will not lead to the prevention or alleviation of any human disorders.
A related matter, also ethically dubious, is the possible future use of living tissues taken from normally grown and subsequently aborted human fetuses, for therapeutic transplantation into adults.
First, let us be clear about some terminology. A developing human being is called an “embryo” from conception until the end of the third month of pregnancy, when its name changes to “foetus.”
Early embryos
The experimental approach to science consists of advancing knowledge by testing hypotheses, and then proposing new theories on the strength of the results obtained. This approach is conspicuously absent from vague notions of advancement of reproductive physiology through experimentation with human embryos.
The principal claim made is that research will increase the success rate of IVG as a treatment for some types of infertility. At present, only about 20 per cent of attempts to introduce embryos into infertile women are successful. The failures occur because the uterus does not always react favourably to the embryo, which then fails to implant and cannot continue to develop. The same thing happens quite frequently with embryos conceived in the normal way (in vivo), though authorities disagree about the frequency of such early spontaneous miscarriages.
The cellular and chemical mechanisms of the implantation of embryos, whether conceived in vitro or in vivo, have been under investigation for at least 500 years, so a great body of knowledge is available and continues to accumulate. The strategy of such research devolves largely around the study of endocrine glands, hormones and the uterus, in laboratory animals. Isolated early human embryos could not provide answers to questions concerned with the physiology of implantation in the human uterus.
The research of the past 50 years would have to be repeated using adult women in conjunction with little embryos, and even the most ardent test-tube abortionists have not had the temerity to propose such action! However, there is no reason to suppose that any knowledge would be obtained from direct human experimentation that could not be validly inferred from work with animals.
Prevention?
Research with human embryos has also been suggested for “preventing” a variety of diseases that can be diagnosed before birth. These include chromosomal abnormalities such as Down’s Syndrome or “mongolism,” and some rare inherited conditions, often called “gene disorders.”
When suspected, some of these diseases can be diagnosed in mid-pregnancy by examining cells taken from the fluid in the uterus. If the child is found to be ill, it is often killed in the uterus at the request of the mother.
This could be avoided, say the protagonists of embryo research, by arranging for all conceptions with risk of abnormality to be accomplished by IVF. The embryos could then be tested, and the abnormal ones discarded. Thus, the death sentence would be carried out “in the test-tube, rather than inside the mother.
They claim that large numbers of early human embryos will have to be “used” to develop the diagnostic techniques, which necessitates the study of samples consisting of only a few cells. This is nonsense. Human embryos would be far too variable to serve as useful subjects in research of this kind.
The correct procedure is to use small clones of cultured cell-lines for perfection of the small-scale molecular biological methods. If cells of early embryos were needed in a later stage of the research, the scientifically valid source would be inbred mice, which naturally produce a dozen or more identical embryos at a time.
There is something very wrong with the ultimate goal of the kind of research reviewed above, which is directed towards making the diagnosis and then killing the patient. This is neither prevention nor cure!
The true prevention of congenital abnormality consists of not allowing the conception of an afflicted individual. This can often be achieved through genetic counseling. In the future it may well be possible to select for health before fertilization. One way of doing this would be to purify semen by removal of the sperm cells that carry the abnormal gene. Research to develop this kind of technique would not require human embryos.
Treatment
The treatment of the abnormally developing embryos is a touchy problem for research workers, but it is potentially feasible. The molecular biologist’s approach is to replace the abnormal gene with its normal counterpart: “gene transplantation.”
An enormous amount of research (mainly with insects and mice) will be needed before such a technique can be tried out in man. The other strategy, perhaps a more realistic one, is to interfere with the expression of the abnormal gene. Such treatment is based on thorough understanding of the biochemical and other abnormalities of the disease. A reasoned procedure for reversing the abnormality is confirmed experimentally, and then tried in clinical practice.
Phenllketournia is a simple example: this rare inherited type of mental retardation can be cured by a special diet during the critical period of development of the brain in infancy. Similarly, the abnormal development of the brain in cretinism can be corrected by timely administration of the missing thyroid hormone. No research into the true treatment of developmental disorders involves experimentation with human embryos.
One does not have to be a scientist or a doctor to see the flaws in the arguments brought up to support research with human embryos. Indeed, one wonder if those who would do such research are motivated by anything more than the desire to do something that looks fashionable and attracts the attention of the press.
Transplantation of foetal tissues
Adult brain tissue does not survive transplantation, but it has been realized for some 15 years, that small pieces of brain can be transplanted through donor and recipient are genetically different. Furthermore, the transplanted nerve cells can, in some circumstances, from functional connections with appropriate parts of the recipient brain.
Several diseases of the human nervous system are due to the death of specific populations of nerve cells, and such diseases are potentially treatable by replacing the missing cells.
The greatest amount of attention has been paid to Parkinson’s disease. This is a fairly common disorder of movement due to loss of cells from a part of the brain known as the substantia nigra.
In animals, it is possible to produce a comparable disorder by surgical destruction of the substantia nigra. The experimental disease is alleviated by a suitably positioned transplant of cells from the substantia nigra of foetal brains. A litter of 10-12 rat fetuses provided enough cells to make a functionally adequate graft for an adult recipient rate.
Parkinson’s disease in people is treated medically, by supplying a drug that replaces the chemical signals normally generated by the cells of the substantia nigra. This relieves the condition but does not cure it, because the underlying loss of nerve cells continues. A graft of healthy foetal nerve cells of the right kind might be curative, just as it seems to be in the animal models. A simpler and less contentious source of cells for transplantation is part of one of the patient’s own adrenal glands.
It has been known for 20 years that these adrenal cells are potentially capable of growing into ordinary nerve cells using the same type of chemical communication as the cells of the substantia nigra.
The first human adrenal-to-brain transplants, in Sweden, provided only transient alleviation of the Parkinsonian symptoms, but more recent operations in Mexico and the USA may have been more successful. Thus, the apparent need for foetal donor tissue may have been circumvented for the transplantation therapy of Parkinson’s disease.
Sinister possibilities exist, however, for the experimental treatment of other degenerative diseases of the nervous system.
Alzheimer’s disease is responsible for the mental deterioration once thought to be an almost normal accompaniment of ageing. Authorities disagree about the location of the nerve cells whose death triggers widespread degeneration in the brain, but it is widely believed that the missing cells may belong to a type that could be replaced by foetal grafts.
Huntington’s chorea, an inherited abnormality of movement with associated dementia, is another disease that might, one day, be amendable to treatment with grafted foetal brain tissue.
For Alzheimer’s and Huntington diseases, there is nothing in the adult that is equivalent to the adrenal cells that have been transplanted into the brains of patients with Parkinson’s disease. Any surgical treatment of Alzheimer’s or Huntington’s disease would be based on extremely speculative premises, because there are not equivalent diseases that can be reliably produced in laboratory animals.
A code of ethics for the use of foetal grafts must be developed. It is unlikely that spontaneously aborted human fetuses will be used as donors, because they arrive at inconvenient times and may be infected or otherwise abnormal. Embryos conceived in vitro will be unsuitable because they can be kept only until the stage at which they might implant. Foetuses deliberately aborted in the fourth and later months of pregnancy could therefore become valued articles of commerce in the next few years.
Even if transplantation has no eventual place in the management of degenerative diseases of the brain, there will always be people wanting to try desperate remedies.
Furthermore, foetal tissues other than those of the brain may also be demanded for transplantation. Aborted fetuses are small, so several would be needed for each recipient.
It may not be simply a matter of making use of abortions that would be done anyway – there is a real risk of pregnancies initiated solely for the purpose of selling organs and tissues for transplantation into ailing adults.
Conclusion
Experiments with early human embryos cannot be expected to contribute anything useful, either to fundamental knowledge of the reproductive process or to the prevention or relief of human suffering. The money taken from taxpayers to fund fashionable but worthless “research” would be much better spent on genuinely scholarly investigations, especially in the basic medical science departments of universities.
Foetal-to-adult grafts of brain tissue have provided a valuable experimental tool for the science of developmental neurobiology. Therapeutic use of such grafts in man is a future possibility. It is now necessary to provide protection for fetuses that might be unscrupulously conceived, grown and killed in order to provide organs for transplantation.
