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18 septembre 2007 2 18 /09 /septembre /2007 06:18
Distinguished Bishops, Ladies and Gentlemen,

it is a distinct honor and privilege to speak to you about the PGD procedure in Germany and the related issue of unprotected human pro-nuclei.

1. Basics
“Preimplantation genetic diagnosis (PGD) is the diagnostic procedure for an embryo in vitro prior to intra-uterine transfer with regard to changes of genetic substance that would otherwise lead to severe malformation.”  The goal is avoidance of pregnancies with undesirable embryos.

This picture shows an egg-cell with the first polar body which develops during maturation and also a sperm. After penetration of the ovum by the sperm, a second polar body develops and two pro-nuclei become visible. The first and second polar bodies are located below the zona pellucida. The egg-cell is now in the 2 pro-nuclei-stage (pro-nuclei).

One day after the union of ovum and sperm the maternal and paternal genetic materials are fused together. The new genetic individual is created. From this moment onward the embryo is called “zygote”. This early stage is known as blastomere. It is represented here by separate cells.

The pro-nucleus or the embryo has to be available in a test-tube. Both, In-vitro-fertilization (IVF) and Intracytoplasmatic-sperm-injection (ICSI) are artificial, reproductive processes.

Two kinds of biopsies are widely used:
a)    By means of the polar body biopsy the first and second polar bodies are removed. This procedure is limited by its exclusive reliance on maternal genetic material. German reproductive medicine favors this method as it does not stand in conflict with the existing German Embryo Protection Law (GEPL).
b)    Blastomere biopsy is employed when the embryo has anywhere from 4 to 10 cells; of that total 1 or 2 cells are removed. Blastomere cells are ‘totipotent’, i.e. each cell is capable of developing into a complete individual.

2. PGD in Germany and international data base
In 1995, Professor Klaus Diedrich was first to request permission for carrying out a blastomere biopsy, having submitted a proposal on behalf of so called “high risk couples” to the Ethics Commission at the Medical University of Lubeck. In this case both parents carried a gene mutation called ‘cystic fybrosis’. The request was denied on statutory grounds. Since May 2001 the Bonn University Clinic offers the polar body diagnostic procedure for women of advanced age who have long desired a child. To improve the rate of success this program scrutinizes the pro-nucleus stage for chromosome abnormatilities (‘Aneuploidy –Screening’). The first child was born in February 2002.

A PGD data base of the European Society of Human Reproduction and Embryology (ESHRE) for the period of 1994-2001, that draws on reports of 25 collection points in Europe and the United States has documented 2,074 cycles of treatment, which were undertaken by 1,561 couples. The record shows 309 pregnancies that led to 215 births yielding a total of 279 children. The distribution was as follows: 156 single children, 54 twins (25%) and 5 triplets. A total of 27,786 egg-cells were taken, which amounts to 13.4 per cycle. The “Baby-take-home-Rate” of 10.37% (215/2074) has exerted a strong appeal to parents.

In addition to the groupings “High-risk Couples” and “Aneuploidy-Screening”, two further categories need mentioning: “Family Balancing”, a selection technique that eliminates embryos of the undesired gender. “Designer Babies” are children selected from among 80 to 100 embryos and designated to serve after delivery as immunologically suitable providers of healthy cell material for siblings who suffer from disease.

3. Hurdles for mother and child
It is a long way from the PGD treatment cycle to actual birth.
First off, a sufficient number of egg-cells must be initiated and aspirated. Secondly, there is the hurdle of successful fertilization and the actual locating of the desired embryos. ESHRE recommends ICSI for all PGD cycles to avoid contamination. A study undertaken in Western Australia has documented that the risk of severe birth defects is twice as high among babies born after ICSI or IVF than among those subject to natural conception. One half of all embryos do not survive biopsy and diagnostic procedure. Only 4,598 out of 11,329 embryos were declared ready for transfer. However, only 3,657 were actually transferred. Analysis of the spare embryos which were not transferred showed that in 8% the original result could not be confirmed.

If several desired embryos are available, a quick decision is required to determine which of them is to be selected for uterine transfer and what shall be done with the remaining embryos. Those intended for later transfer can be subjected to deep-freezing (cryopreserved) .It is estimated that some 500,000 embryos are in deep-freeze storage in the United States. In Germany, by contrast, embryos may only be placed in frozen storage when an emergency arises. For 2001, the German IVF-Register listed 74,000 frozen pro-nuclei. Deep-freeze raises a host of ethical and legal problems, such as the right of disposal after the death or separation of the parents. Germany also imposed a limit of three embryo transfers per cycle.

Pregnancies resulting from artificial fertilization are generally considered risky and are therefore subject to elaborate prenatal diagnostic procedures. Invasive prenatal diagnoses carry a risk of abortive results (between 0.5% and 1%). ESHRE data document six cases of faulty diagnostics in a total of 309 PGD engendered pregnancies. Four of those six led to abortions. In addition there is evidence of nine fetocides that were carried out to reduce pregnancies with multiple individuals. “A fetocide does constitute a previously unacknowledged risk to the remaining children.”  Such a fetocide could well contribute to the Post-Abortion-Syndrome (PAS).

The final hurdle is birth itself. In Germany, termination of pregnancy is legally permitted until the very moment of birth. Time will tell whether PGD-Parents will have to cope with new symptoms, esp. when faulty diagnoses and lack of clear information led to decisions that look deplorable in retrospect.

4. Christian social doctrine
Pope John Paul II. declares in ‘Evangelium Vitae’ that [both] the capacity of human judgement and the societal apperception of the enormous transgression of premeditated killing is progressively weakening. “The willful decision to deprive an innocent human being of his life is morally speaking always disgraceful and can never be justified.” With regard to the right to life “each innocent human creature [is] equal to all others. Such equality forms the basis of every true social relationship”.  The decision that parents make in favor of PGD may well be based on good intentions and may have benign consequences, namely the birth of a child. However, any killing is “radically incompatible with the love of God and the dignity of man, who was created in the divine image”.  The German philosopher Juergen Habermas sees PGD as violating “the conditions of reciprocity governing communicative understanding” and adds, “while ignoring the premise of consensus, parents have made decisions solely in accordance with their own preferences, as though they were ruling over a thing”.

The instruction ‘Donum Vitae’ (1987) considers IVF a violation of the rights of the child to have its specific origin in the union of the marital act. Instead, the child becomes the “product of an intervention through medical techniques” and is relegated to the status of an object.  It is not only the threshold of the PGD procedure that stands against the symmetry of relations but each and every IVF treatment as well, because the very beginning of  human existence is subjugated to the will of the parents and the skills of reproductive medicine.

In contrast to PGD, pre-natal diagnostic procedures are morally acceptable, “if they represent no disproportionate danger for child and mother, and aim at early therapy or enhance a well-tempered acceptance of the unborn”. If such diagnostic is, however, pursued on eugenic grounds in order to selectively abort the impaired unborn, then the motives are “malicious and highly reprehensible “. 

At the time of publication of ‘Donum Vitae’ (1987) polar body diagnosis was not yet feasible. The document states, “Each human being must be respected as a person from the very beginning of its existence”. In a footnote this explanation is added: “The biological identity of a new human individual has already been constituted in the zygote that has come forth out of fertilization”.  This important teaching of the Church should be amended in order to forestall the impression that pro-nuclei are free to be used in PGD procedures or selection and deep-freeze conservation.
5. Political challenges
Legislatures must grasp that PGD will either be comprehensively adopted or not at all. Advocates of PGD – including the majority of members of the National Council on Bioethics - have asserted that PGD is justifiable “in analogy to the medical indication for the termination of pregnancy according to Pre-Natal Diagnostic”. As the argument fashioned above has shown, PGD and Pre-Natal Diagnostic differ profoundly in regard to context and bodily strain.

The last 15 years have seen the emergence of a trend that makes the obligation to have a healthy child. Pre-Natal Diagnostic had appeared to be a step toward further choices, but has been turned into a new burden of responsibility for women.   The German Council of Handicapped Persons ( Deutscher Behindertenrat ) has echoed the warning of the Conference of Bishops against PGD. The Council sees PGD as “the continuation of a logic that has already been expressed in the discriminating criteria of indications which sanction abortions.”

6. In conclusion
It is a matter of urgency for the legislative branch to enact a statutory barrier against PGD in the form of Polar Body Biopsy. The work of Professor Gunter Rager of Fribourg –Switzerland has proposed to classify the fertilized egg-cell as an individual in the biological sense; paired with the research of Professor Magdalena Zernicka-Goetz of Cambridge –UK, it would thus be possible to place pro-nuclei – just like embryos – under the protective umbrella of the constitutionally enumerated human dignity.

With the penetration of the egg-cell by the sperm the process is set into motion. The Church should take steps to amend ‘Donum Vitae’ and Christian Social Doctrine should become committed to the protection of human pro nuclei and embryos.

Thank you for your attention

Dr. Mareike Klekamp
Rome septembre 2006
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