Eubios Journal of Asian and International Bioethics - Eubios Ethics ...

14 Eubios Journal of Asian and International Bioethics 22 (January 2012)
the same year a healthy boy was born in Italy as the
result of in vitro fertilization and embryo transfer on a
healthy ovum resulting from comprehensive oocyte
screening using array CGH. The task force that was
involved in this pilot study consisted of ESHRE president
Luca Gianaroli and Dr. Christina Magli of the Italian
Society of Reproductive Medicine (SISMER) in Bologna,
Bonn University’s Dr. Markus Montag and Prof. Hans van
der Ven, with the analysis results of their pilot study
presented at the ESHRE 2010 annual general meeting in
Rome. The study reported that “the average age of
participating patients in the clinical test study was 40” and
claimed that “the method was useful for women over 37
and for those who had suffered from repeated
miscarriage”.
This PGD method of polar body analysis does not
require embryo biopsy essential in common PGD, it is a
non-invasive method for the non-inseminated egg cells
that are to be diagnosed, and it is an effective method for
increasing pregnancy rates in women of advanced age
with an elevated occurrence rate of ovum chromosomal
disorders. For this reason, the Reproductive Genetics
Institute 13 in Chicago, USA, reports a high number of
cases in which polar body analysis PGD has been
performed. Naturally, with polar body analysis PGD, only
the genetic information of the mother can be obtained.
5. Is polar body analysis PGD the selection of life?
The problem arises as to whether or not the JSOG
non-endorsed polar body analysis PGD as a precaution
against “miscarriage thought to be caused by numerical
chromosomal disorders” is in fact the selection of life. In
actuality, a JSOG report concerning the appropriateness
of polar body analysis PGD as a precaution against
“miscarriage thought to be caused by numerical
chromosomal disorders” does not currently exist.
Well, would it be possible to utilize polar body analysis
PGD in order to avoid the ethical critique of selection of
life accompanying the common PGD method requiring
embryo biopsy by FISH and CGH?
No. And the reason for this answer is that, whether it is
the common PGD method using FISH or CGH, or polar
body analysis PGD using CGH, eventually an
inseminated egg cell has to be chosen. For example, in
the German speaking countries where the beginning of
life is perceived at the moment of insemination, in order
to increase the accuracy of the examination, both the
primary polar body excreted by an oocyte prior to
insemination (formed during the primary meiotic division
process of the primary oocyte) and the secondary polar
body excreted after insemination (formed during the
secondary meiotic division process of the secondary
oocyte) are normally used in the diagnosis, despite the
fact that polar body analysis PGD is implemented in
order to avoid the ethical criticism of the selection of life
accompanying the common PGD method requiring
embryo biopsy. At the moment a secondary polar body
excreted after insemination is used, polar body analysis
13 Kuliev A, Cieslak et al: Chromosomal abnormalities in a
series of 6,733 human oocytes in preimplantation diagnosis for
age-related aneuploidies. Reproductive BioMedicine Online
6(11): 54-59, 2003.
PGD is converted from non-inseminated egg cell
diagnosis into inseminated egg cell diagnosis.
In short, polar body analysis PGD not requiring embryo
biopsy is ethical in the sense that it does not entail
inseminated egg cell collection, but, in the sense that
eventually inseminated egg cells are selected, its ethical
evaluation does not differ much from common PGD.
However, as previously stated, even in the natural
circumstances of the womb, the selection of life occurs.
Concretely speaking, chromosomal disorders (structural
and numerical) frequently occur with inseminated egg
cells under natural circumstances. Consequently,
inseminated egg cells with chromosomal disorders, either
do not become implanted in the uterus, or abort even
when they do become implanted. There are cases in
which this natural screening process is sidestepped and
pregnancy occurs, but the number of such cases is
extremely small.
Based on the above facts we can conclude that, the
current JSOG non-endorsed polar body analysis PGD
aimed at preventing “miscarriage thought to be caused
by numerical chromosomal disorders” is a selective relief
action for the precious few inseminated egg cells that are
able to be saved and should not be considered the
selection of life, as with the JSOG endorsed embryo
biopsy PGD used for patients suffering from “habitual
miscarriage (including recurrent miscarriage) thought to
be caused by structural chromosomal disorders”.
Now, why is so much attention paid to CGH as a
substitute for FISH? This is because CGH 14 makes it
possible for all chromosomes to be very accurately
examined, whereas FISH only allows us to examine the
twelve chromosomes 8, 13, 14, 15, 16, 17, 18, 20, 21,
22, X and Y. It is not due to any ethical reasons.
Incidentally, in the German speaking countries where
collecting inseminated egg cells has been prohibited,
polar body analysis PGD by FISH, PCR and CGH has a
history of being implemented for ethical reasons. The
polar body analysis PGD by CGH notwithstanding,
compared to blastocyst (inseminated egg cells) embryo
biopsy PGD by CGH, the accuracy level of analysis using
CGH is considerably lower. In Germany, however, where
people involved in reproductive medicine are greatly
troubled by the low diagnostic accuracy level of polar
body analysis PGD, that appeared on the scene as a
substitute for embryo biopsy PGD, in 2010 the supreme
court ruled (dated 6 July 2010) that embryo biopsy PGD
was not illegal. Consequentially, the German
reproductive medicine community, with PGD by polar
body analysis as its mainstream, will draw attention in
order to see if they will, in future, advance towards the
endorsement of PGD by embryo biopsy.
14 Progress is also being made towards the possibility of
implementing array CGH in searching for numerical disorder in
all chromosomes by means of genetic chips. ( Wells D,
Alfalawati S, Fragouli E: Use of comprehensive chromosomal
screening for embryo assessment: microarrays and CGH. Mol
Hum Reprod 14: 703-710, 2008.)