2021 Bioethics Law: Pre-implantation Genetic Diagnosis (PIGD)
I. What exactly is PIGD?
PIGD is a screening technique for embryos. This biological diagnosis is conducted in vitro prior to the possible transfer of the embryo into a uterus. It can enable the detection of genetic and chromosomic anomalies. PIGD involves de facto in vitro fertilization (IVF) in order to conceive the embryos, and therefore the collection and preservation of gametes beforehand (sperm and oocytes) from the parents. Resorting to an ART procedure (ovarian stimulation and puncture, IVF…) is inevitable.
This technique, which has been authorised since 1994, is conducted using cells drawn directly from the embryo, a few days after fertilization, before or after a freezing period. Despite this removal, the embryo will continue to develop.
In 2021, 305 babies were live-born (from 290 childbirths) following a PIGD procedure. To understand the growth in the number of cases of PIGD, there are now six times more than in 2007, when 50 babies were born following its use.
A. Who is concerned by PIGD?
In France, PIGD is used essentially in a context of personal or family antecedents. Its use by people who wish to become parents is authorised exceptionally under certain conditions:
- When it is known that the couple (or the single woman applying for ART involving an anonymous sperm donation), due to family history, has a strong probability of giving birth to a child suffering from a particularly serious genetic disease which is recognised as incurable at the moment of diagnosis.
- If the genetic anomaly or anomalies responsible for the disease have been identified previously and precisely, in one of the parents or one of their immediate ascendants (in the event of a seriously invalidating disease which is revealed late and which prematurely threatens life expectancy).
- The diagnosis cannot have any purpose other than searching for the disease as well as the means of preventing and treating it.
In simple terms, although resorting to PIGD is authorised for a couple who have already had a child carrying a disease, the diagnosis may only be used to search for the presence or absence of that precise pathology in the embryos and not to look for any other indications.
B. What becomes of the embryos which have been subjected to PIGD?
If the embryo is free of the pathology concerned, it may be decided to implant it in the uterus or to freeze it for subsequent implantation. If the anomaly or anomalies are found on the embryo, it is destroyed or the couple or woman may agree to donate it for research.
C. Which are the indications for which PIGD is authorised and possible?
The Biomedicine Agency (ABM) provides a list of the indications which qualify for a pre-implantation genetic diagnosis in France. In 2021, a total of 403 different genetic diseases have benefited from diagnostic technique development with a view to PIGD. Obviously, this figure is increasing all the time, whenever new anomalies become detectable and identifiable. Among the pathologies most frequently sought, is mucoviscidosis, Huntington’s disease, X fragile syndrome, sickle-cell anaemia, certain muscular dystrophies etc.
II. Resorting to PIGD in France in a few figures
Each request for PIGD is examined by a multidisciplinary pre-natal diagnosis centre (CPDPN). 1366 requests were examined in 2021 (the latest figures available from the ABM). This figure is higher than for the previous years (in 2017, there were 1018. In 2015, 766).
In 2021, 869 requests were accepted. Therefore, slightly less than two thirds of requests (63.6%) nationally are recognised as being eligible for PIGD. This proportion, on the other hand, is decreasing regularly. Therefore, on average, there are more requests but less acceptable cases. There is also a strong disparity between the different centres. Nantes reports an acceptance rate of 81.2% whereas in Paris it is 52%.
III. The special case of a Double PIGD: PIGD-HLA, the so-called “double-hope baby” technique
The designer-baby technique, sometimes known as the “double-hope baby” requires the generation of a very large number of embryos in vitro, followed by double screening. It consists in conducting a double diagnosis. First, to select the embryos which are exempt from the given pathology (suffered by a child of the couple). Then, among those embryos, a check is made to see whether or not they are immunologically compatible with the child already born. Whence the term HLA attached to PIGD. HLA signifies: “human leucocyte antigen” and contains a major part of the human immunity system.
Subsequently, if a compatible healthy embryo has been conceived, it will then be implanted in the mother’s uterus. Once the child is born, stem cells will be taken from this “double-hope baby”, first from placenta blood or, later on, from its bone marrow, to be administered to the elder sick child. The probability of achieving a compatible healthy embryo is very low (around 10%). When this is combined with the habitual high failure rate experienced with ART, the chances of a successful pregnancy are therefore quite minimal.
Moreover, the progress achieved in the collection, storage and donation of umbilical cord blood provides an ethical means of meeting this type of therapeutic need, making the PIGD-HLA technique even more unacceptable. Nowadays, the probability of finding a compatible donor is increasing year by year thanks to the solidarity network woven by worldwide registers. Today, umbilical cord grafting is an operational practice and represents some 8% of the total grafts of haematopoietic stem cells in France (this proportion rises to 27% of grafts in children).
This technique poses serious ethical and moral problems. It considers the birth of a child, not as an end in itself, but as a means. The mere fact of rejecting healthy embryos (but which are not HLA compatible) shows that the child to come is not primarily desired for itself, but in fact for another. This technique can give parents false hope.
Moreover, it is difficult to imagine the psychological burden to be borne by the child regarding the role set for it: to be the saviour of its brother or sister. What impact could that have on the construction of the child’s personality? Knowing that it owes its very existence to the result of a screening process, whose aim is to save another, is far from innocuous. Added to this is the possibility that the bone marrow punctures will need to be repeated throughout its lifetime. What about if the therapeutic graft is a failure, what then becomes of the child, and the family with it?
Umut-Talha, the first French “medicine child”, was born in 2011, conceived in order to treat a sister suffering from beta-thalassemia, a genetic disease due to a haemoglobin anomaly. Since then, requests have always been extremely rare, a mere 38 between 2006 and 2014. Hôpital Béclère, the only hospital to have practiced PIGD-HLA, even discontinued the procedure in 2014 as the activity was considered too lengthy and arduous, both for the couples and for the medical teams involved. The technique is rarely proposed, rarely requested and rarely performed.
In the new bioethics law adopted by the French parliament in 2021, this measure was however maintained although some MPs sought to delete it. Certain conditions have even been relaxed. Indeed, the 2021 law no longer demands that all healthy embryos stored for a couple should be implanted before attempting any new IVF (article L 1231-4 of the public health code) in order to conduct a double PIGD, which was stipulated by the law previously.
IV. What are the stakes involved in PIGD?
In certain nations, such as the United States, PIGD is already used for selecting embryos according to their sex, aesthetic criteria (eye colour) and even to choose embryos suffering from a handicap. A real market has developed around this eugenic “service”. Additionally, a survey has revealed that 3% of parents suffering from genetic deafness intentionally choose to resort to PIGD-IVF in order to select an embryo, also suffering from deafness. The parents wish to pass on their handicap as a heritage, for their child to share the same means of communication.
Currently in France, the context of PIGD is limited to hereditary anomalies only, which are particularly serious and incurable at the time of diagnosis. But the logic inherent in the technique is intimately dependent on embryo screening. Already, some people wish to obtain an extension of the indications, in particular to open up its potential to others who are not suffering from hereditary genetic diseases. In particular for PIGD-A (where A stands for aneuploidia, which means an abnormal number of chromosomes, which is the case in trisomy).
In France, strong pressure is being applied for ever more widespread screening. A slippery slope towards PIGD for EVERYTHING and for EVERYONE, against the backdrop of an increasing myth in the quest for the “perfect baby”. The slide is already well under way. First, these tests were authorised only to track very serious diseases. Then less serious. Then, simple predispositions.
When embryos are conceived in vitro, by IVF, in the context of an ART procedure for couples suffering from infertility, the embryos are in a way made available to biologists. Some people are pleading for these embryos to be screened prior to implantation. The mechanical and technicist logic is established. Since the technique is available, why not use it, and thus, avoid storing and implanting embryos which may be suffering from trisomy, for instance, since that condition would be detected subsequently during pregnancy, and could lead to a therapeutic abortion, which is more traumatic for both the pregnant woman and the medical staff.
Thus, the slide towards consensual technological eugenics has never been so relevant. The ethical stakes are immense: it constitutes a wilful breakdown towards a form of quality control of embryos, in the absence of any identified risk. For example, which trisomies would be eligible for the test? Which ones would pass through the selection screening?
Finally, PIGD is not a foolproof diagnosis. There is a risk of false positives as well as false negatives. There may also be cases of mosaic embryos, where cells coexist in a given embryo which give different diagnosis results.
Within this PIGD technique true stakes for humanity are being played out: the manner in which a society considers childbirth and childcare. And the consideration of human procreation, subject to ever increasing pressures from the technique, the market and the law of the survival of the fittest. That, in fact, of refusing to submit life to biotechnologies.
