Experts join the German Ethics Council to discuss and compare the practice of preimplantation diagnosis in various European countries

The hearing began with a report by Luca Gianaroli, Chair of the European Society of Human Reproduction and Embryology (ESHRE), on the state of the art of PGD as reflected in the register kept by the ESHRE for more than ten years now. Data from 57 of the current worldwide total of over 100 centres is held and evaluated in the register. Between 1999 and the period covered by the most recent report (the 2007 treatment year), some 28 000 treatment cycles were carried out and 4047 children were born after embryo screening. The cells to be tested were extracted on the third day in approximately 99.5% of cases. Because these cells are assumed to have the potential to develop into an independent embryo, this practice is prohibited in Germany. However, the speaker noted an increasing level of interest in the possibility of conducting the test on blastocysts – that is, in screening on about the fifth day of embryo development. By then more cells could be obtained, and furthermore these would have been destined only for subsequent placenta formation.

With regard to the practice of PGD in Belgium, Paul Devroey, a specialist in reproductive medicine, explained that the procedure for approval of any diagnosis was difficult but transparent. PGD was performed at seven licensed IVF centres in collaboration with a human genetics centre. Additional requirements were the provision of advice to the couple and favourable evaluation of the case by a specialist in reproductive medicine, a geneticist, a psychologist and, where necessary, an ethics committee. As for an official list of permitted indications, this did not exist.

The next speaker was Emily Jackson, Professor of Law and Deputy Chair of the United Kingdom Human Fertilisation and Embryology Authority (HFEA). The Authority is responsible for issuing the licences required by centres offering PGD. It also decides which genetic and chromosomal disorders qualify for PGD. Professor Jackson explained that, in the consultative procedure, account was taken of the situation of the couple, while the opinions of various experts such as medical practitioners and patient groups were obtained. For particularly controversial types of diagnosis, such as testing for breast cancer gene markers, the public too were increasingly involved in the consultation process. However, once a given test had been recognized, any licensed centre could make use of it without applying to the HFEA for approval in each individual case.

Patrick Gaudray, a geneticist and member of the French National Ethics Advisory Committee (CCNE), reported on the French model, which imposed strict limits on PGD that could be modified only by amendments to the Law on Reproductive Medicine. At present only three centres were licensed for PGD, which was permissible solely for families already affected by a serious and incurable genetic disorder. Instead of a list of specific pathogenic predispositions for which screening was permissible, each individual case was assessed by a standard procedure.

Unlike France, Belgium and the UK additionally permit testing for chromosomal disorders that are not already present in the parental genome but arise only in the course of gamete formation or fertilization. According to the most recent ESHRE data presented by Dr Gianaroli (for 2007), screening of this kind was conducted in just under 64% of all cases of PGD, and was therefore much more frequent than diagnoses of specific inherited pathogenic dispositions. However, Professor Devroey, Professor Jackson and Dr Gianaroli pointed out that according to recent studies, contrary to earlier expectations, the birth rate was not improved by screening. For this reason, this approach must still be deemed experimental, although there were indications that more recently developed screening methods might yield better outcomes in the future.

Members of the German Ethics Council and the many members of the Bundestag (German Federal Parliament) attending the hearing put questions on further aspects to the experts following their presentations. Particular interest was expressed in the number of embryos used for a PGD. In most cases this number significantly exceeded the maximum of three per IVF cycle permitted, according to the prevailing view, by the German Embryo Protection Law. Another issue raised concerned the details of the process of deciding for or against screening for the causes of specific genetic disorders. Given the differences of approach to preimplantation diagnosis and its assessment, the experts considered that a decision compatible with the relevant society and the various positions represented in it had to be taken in accordance with a democratically legitimized procedure.

More information on the hearing (in German) can be accessed at http://www.ethikrat.org/veranstaltungen/anhoerungen/
praeimplantationsdiagnostik.