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Era of 'unborn mother'
looms as scientists use aborted fetuses to grow human eggs |
London
Independent
01 July 2003
Almost every day a scientific or medical development seems to bring
new promise and controversy to mankind; none more so, perhaps, than
in the field of human fertility.
A quarter of a century ago the first test-tube
baby, Louise Brown, was born. Now scientists have raised another
startling prospect - "unborn mothers".
The notion that children can derive from
human matter that has not itself been born sounds the stuff of science
fiction. Yet it has moved a step closer with research showing that
it is possible to extract ovarian tissue from aborted foetuses for
in-vitro fertilisation (IVF) treatment.
Scientists announced yesterday that they
have been able to remove immature ovaries from four-month-old foetuses.
The theory is that they can then be stimulated in the test tube
to go through the later stages of development before the creation
of fully mature eggs.
But such a scenario raises grave ethical
questions about the possibility of creating children whose biological
mothers were never born. When a high-powered committee of British
ethicists considered this possibility in the early 1990s it took
the view that any child created by such a procedure would not be
able to come to terms with the idea of deriving from aborted foetal
tissue.
However, it is clear that the increase
in demand for a supply of healthy human eggs - which are not easy
to "harvest" from even the most fertile women - is causing
several groups of scientists around the world to explore the possibility
of using aborted foetuses.
Medical researchers from Israel and the
Netherlands have now gone further than any previous attempt at experimenting
with ovarian tissue from human foetuses. They artificially stimulate
fluid-filled sacs or follicles within surgically removed ovaries
to undergo several stages of development.
Normally an egg develops within the follicle
as it goes through four developmental phases - the primordial, primary,
secondary and pre- ovulatory stages - before it is released from
the ovary into the Fallopian tubes.
The scientists said they had managed to
culture foetal ovaries in test tubes to enter the start of the secondary
stage. This is when the ovarian follicles begin to produce the female
sex hormones necessary to develop and mature the eggs.
Tal Biron-Shental, a gynaecologist from
Meir Hospital-Sapir Medical Centre in Kfar Saba, released the findings
of the study at the annual meeting of the European Society for Human
Reproduction and Embryology in Madrid.
Dr Biron-Shental said that the researchers
obtained ovarian tissue from seven aborted foetuses aged between
22 and 33 weeks and managed to keep slices of the ovaries alive
for four weeks, long enough for the follicles to develop to the
stage when they began to produce the female hormone oestradiol.
"We didn't have mature oocytes, we
had follicles that changed from primordial follicles and survived.
We had E2 [oestradiol] secretion which means that we had more secondary
follicles which means there was a development," Dr Biron-Shental
said.
"This is the first report showing
survival of second and third trimester human foetal ovarian follicles
in culture with E2 production. E2 was probably secreted from the
few secondary follicles in the cultured slices," she told the
meeting.
The study in Israel was run with the veterinary
department of Utrecht University, which supplied some of the culture
medium for the test-tube development of the ovarian tissue. Full
ethical approval was obtained prior to the study being carried out,
the scientists confirmed.
"The local ethical committee of our
medical centre approved the study and informed consent was obtained
from the mothers," Dr Biron-Shental said. "We had different
kinds of aborted foetuses with all kinds of malformations. Of course
we could not use normal foetuses for such experiments because it
is controversial enough," she explained.
However, there was one exception. "We
had one aborted foetus that was completely abnormal and the abortion
took place because the mother of the foetus had severe psychiatric
problems. There are a lot of ethical questions on this point. Since
it is still preliminary results we don't have all the answers for
those ethical questions," she added.
Asked how long it would be before she
was able to produce fully mature eggs from foetal ovaries, Dr Biron-Shental
said: "It will still take a long time. I don't know exactly.
"We have an end goal and we continue
to culture follicles from aborted foetuses. We have tried to improve
the culture media and to prolong the culture period. We hope to
get better results and more follicles," she said. "I am
fully aware of the controversy about this, but probably, in some
places, it will be ethically acceptable."
Anti-abortion groups were quick to denounce
the research yesterday. Nuala Scarisbrick of the organisation Life
said the study was morally repugnant. "Who would want to know
that their mother was an aborted baby?" she said.
Françoise Shenfield, an ethicist
at University College London and a former member of the Human Fertilisation
and Embryology Authority, also voiced concerns about where this
sort of research was leading.
"I would be very troubled by this
not only for ethical reasons but for psychological reasons, because
what is the public going to think about where the eggs come from?"
Dr Shenfield said.
A spokeswoman for the HFEA said that the
use of ovarian tissue from foetuses was considered by a committee
of ethicists in 1994, which led the authority to decide that it
would be difficult for a child to come to terms with the idea that
it had been created from aborted foetal material because of prevailing
social attitudes.
"The authority does not consider
the use of tissue from this source to be acceptable for infertility
treatment. But the authority does allow the use of foetal material
to produce eggs for research provided that it is taken only with
full, explicit consent," she said.
Roger Gosden, a leading fertility specialist
working at the Jones Institute in Norfolk, Virginia, said the ethical
issues centre on the issue of informed consent - the foetus cannot
give its consent.
Dr Gosden also questioned whether the
research was necessary because he had demonstrated that it is possible
to obtain ovarian tissue from adult women with the aim of culturing
the follicles in vitro to produce mature eggs.
"I would say that we don't need to
use foetal material. The only advantage in doing so is that there
are a huge number of eggs there, but obviously we have to be very
sensitive to ethical issues," he said.
"We should be able to study foetal
ovaries for research purposes, but it's the application in reproduction
that I have concerns about," he added.
Experiments with mice have shown
that it is possible to mature foetal eggs fully, fertilise them
in a test tube, implant them into an adult mouse and produce healthy
offspring. Some scientists hope to be able to do the same with human
material.
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