 |
|
Should embryos with a hereditary disorder be transferred if no unaffected embryos are available?
July 08, 2008Barcelona, Spain: The numbers of cycles of preimplantation genetic diagnosis or screening are rising steadily in Europe with over 2,700 reported in 2004 (the most recent year for which data are available). Fertility centres are able to screen for a growing number of genetically related conditions, but what should doctors do if no embryos without the targeted condition are available for transfer and the parents request that affected embryos should be transferred instead?
Ethicist Dr Wybo Dondorp told the 24th annual meeting of the European Society of Human Reproduction and Embryology in Barcelona today (Monday): "Parental requests for transferring affected embryos should not be dismissed beforehand as a sign of irresponsible capriciousness. As the couple's primary wish may be for a child, they may reason that if a non-affected, healthy child is not what they can get, they will also be happy with, and good parents for, a child with a condition they at first intended to avoid. Respect for autonomy at least requires taking such requests seriously, even if, in view of all other considerations, doctors decide not agree to the requests."
Dr Dondorp, who is a senior research fellow at the faculty of Health, Medicine and Life Sciences, department of Health, Ethics and Society at Maastricht University (The Netherlands), said that before couples have preimplantation genetic diagnosis (PGD), fertility clinics should discuss the decision-making process and the particular clinic's policy in their pre-test counselling sessions with prospective parents, so that everyone was clear about what the options were in cases where no unaffected embryos could be obtained.
He said the most important consideration was the welfare of the child, particularly taking into account doctors' professional responsibility "to do no harm". "A high risk of serious harm is a contraindication for transferring affected embryos. The present consensus is that where the classical indications for PGD are concerned, doctors should, as a general rule, not transfer affected embryos where no non-affected ones are available. In pre-test counselling it should be explained that if no non-affected embryos are available, the only options are trying a new cycle or being advised to reconsider one's reproductive plans such as refraining from reproduction, using donor eggs or sperm, or adoption.
"The welfare of the child is closely connected to the classical indication for PGD: a serious disease caused by a single gene mutation for which there are no, or limited, treatments, and, in most cases, presenting early in life. An example is an embryo that is homozygous for cystic fibrosis, where the child will definitely have the disease. In such cases it is inconceivable that doctors would agree to transfer these embryos as it would be at odds with their professional responsibilities."
However, as the use of PGD is being extended increasingly to conditions outside the classical range of indications, transferring affected embryos need not always involve a high risk of serious harm. This is obvious where treatable diseases are concerned, such as MCAD deficiency (where people with a faulty medium-chain acyl-CoA dehydrogenase gene are unable to metabolise fat, but can lead a healthy life by observing a strict diet).
"Things are less clear where PGD for hereditary cancer syndromes is concerned. Debate about this is urgent, as centres are already confronted with parental requests to transfer embryos found to have the targeted mutation (e.g. BRCA1 or BRCA2 genes for hereditary breast cancer) in cases where no non-affected ones turned out to be available. How should they respond? That there seems to be more room here to at least discuss the issue has everything to do with the nature of the conditions in question: serious but later onset, incomplete genetic penetrance (not all individuals with the mutation will also have the disease) and availability of some therapeutic options," said Dr Dondorp.
"In the case of PGD for hereditary cancer, room for manoeuvre will depend on a case-sensitive evaluation of aspects relevant to the 'high risk of serious harm' criterion, also in view of the family history. If this approach is acceptable and if further debate leads centres to decide that they would not categorically rule this out, pre-test information about centre policy should be adapted accordingly. It must be made clear that there may be, with conditions, room for shared decision-making about transferring affected embryos. But that does not amount to leaving it to the parents, as doctors cannot avoid their professional responsibility for the welfare of the future child."
He concluded: "However, professionals may still find it difficult to respond to such requests that lead not only to the deliberate conception of a child in need of special care, but also to the very outcome they set out to prevent when offering PGD to a couple. Is it acceptable to use PGD just for trying to have a better result than one is eventually prepared to accept? This fits in with a wider debate about the morally charged nature of PGD and the proportionality of its uses: is it acceptable to use PGD for avoiding treatable disease, such as MCAD, in the first place?"
Together with Professor Guido de Wert, also from Maastricht University, Dr Dondorp is writing a paper to be published in Europe's leading reproductive medicine journal, Human Reproduction, on these issues. This is the first time ethicists have considered the questions that arise as a result of extending the use of PGD to hereditary symptoms such as cancer and MCAD.
European Society for Human Reproduction and Embryology
He said the most important consideration was the welfare of the child, particularly taking into account doctors' professional responsibility "to do no harm". "A high risk of serious harm is a contraindication for transferring affected embryos. The present consensus is that where the classical indications for PGD are concerned, doctors should, as a general rule, not transfer affected embryos where no non-affected ones are available. In pre-test counselling it should be explained that if no non-affected embryos are available, the only options are trying a new cycle or being advised to reconsider one's reproductive plans such as refraining from reproduction, using donor eggs or sperm, or adoption.
"The welfare of the child is closely connected to the classical indication for PGD: a serious disease caused by a single gene mutation for which there are no, or limited, treatments, and, in most cases, presenting early in life. An example is an embryo that is homozygous for cystic fibrosis, where the child will definitely have the disease. In such cases it is inconceivable that doctors would agree to transfer these embryos as it would be at odds with their professional responsibilities."
However, as the use of PGD is being extended increasingly to conditions outside the classical range of indications, transferring affected embryos need not always involve a high risk of serious harm. This is obvious where treatable diseases are concerned, such as MCAD deficiency (where people with a faulty medium-chain acyl-CoA dehydrogenase gene are unable to metabolise fat, but can lead a healthy life by observing a strict diet).
"Things are less clear where PGD for hereditary cancer syndromes is concerned. Debate about this is urgent, as centres are already confronted with parental requests to transfer embryos found to have the targeted mutation (e.g. BRCA1 or BRCA2 genes for hereditary breast cancer) in cases where no non-affected ones turned out to be available. How should they respond? That there seems to be more room here to at least discuss the issue has everything to do with the nature of the conditions in question: serious but later onset, incomplete genetic penetrance (not all individuals with the mutation will also have the disease) and availability of some therapeutic options," said Dr Dondorp.
"In the case of PGD for hereditary cancer, room for manoeuvre will depend on a case-sensitive evaluation of aspects relevant to the 'high risk of serious harm' criterion, also in view of the family history. If this approach is acceptable and if further debate leads centres to decide that they would not categorically rule this out, pre-test information about centre policy should be adapted accordingly. It must be made clear that there may be, with conditions, room for shared decision-making about transferring affected embryos. But that does not amount to leaving it to the parents, as doctors cannot avoid their professional responsibility for the welfare of the future child."
He concluded: "However, professionals may still find it difficult to respond to such requests that lead not only to the deliberate conception of a child in need of special care, but also to the very outcome they set out to prevent when offering PGD to a couple. Is it acceptable to use PGD just for trying to have a better result than one is eventually prepared to accept? This fits in with a wider debate about the morally charged nature of PGD and the proportionality of its uses: is it acceptable to use PGD for avoiding treatable disease, such as MCAD, in the first place?"
Together with Professor Guido de Wert, also from Maastricht University, Dr Dondorp is writing a paper to be published in Europe's leading reproductive medicine journal, Human Reproduction, on these issues. This is the first time ethicists have considered the questions that arise as a result of extending the use of PGD to hereditary symptoms such as cancer and MCAD.
European Society for Human Reproduction and Embryology
Embryos Current Events and Embryos News RSSTestes stem cell can change into other body tissues, Stanford/UCSF study shows
Scientists at the Stanford University School of Medicine and at UC-San Francisco have succeeded in isolating stem cells from human testes.
Motor nerve targeting to limb muscles is controlled by ephrin proteins
A study from a team of researchers including Dr. Artur Kania, Director of the Neural Circuit Development Research Unit at the IRCM, and Dr. Dayana Krawchuk, postdoctoral fellow, shows how a family of proteins present in the developing limb control nerve targeting from the spinal cord to the muscles of the limb.
Snails and humans use same genes to tell right from left
Biologists have tracked down genes that control the handedness of snail shells, and they turn out to be similar to the genes used by humans to set up the left and right sides of the body.
Study of placenta unexpectedly leads to cancer gene
University of Rochester Medical Center scientists discovered a gene mutation that impairs the placenta and also is influential in cancer development, according to a study published online December 16, 2008, in the journal PLoS (Public Library of Science) Biology.
A low dose of caffeine when pregnant may damage the heart of offspring for a lifetime
A new study published online in The FASEB Journal shows that the equivalent of one dose of caffeine (just two cups of coffee) ingested during pregnancy may be enough to affect fetal heart development and then reduce heart function over the entire lifespan of the child.
Harm-reduction cigarettes are more toxic than traditional cigarettes, UC Riverside study finds
Typically, tobacco companies market harm-reduction cigarettes as being safer than traditional "full-flavored" brands, leading many smokers to conclude that the use of harm-reduction brands lowers their exposure to toxicants.
Largest study of fertility patients shows concerns about embryo disposition
Fertility patients who are done having children feel responsible for the stored, frozen embryos left over from their treatment, yet more than half are against implanting the embryos in anyone else, according to a new study by researchers at Duke University Medical Center.
Can you hear me now? How the inner ear's sensors are made
A UCLA study shows for the first time how microscopic crystals form sound and gravity sensors inside the inner ear. Located at the ends of cilia - tiny cellular hairs in the ear that move and transmit signals - these crystals play an important role in detecting sound, maintaining balance and regulating movement.
CSHL scientists discover a new way in which epigenetic information is inherited
Hereditary information flows from parents to offspring not just through DNA but also through the millions of proteins and other molecules that cling to it.
Beta Pictoris planet finally imaged?
A team of French astronomers using ESO's Very Large Telescope have discovered an object located very close to the star Beta Pictoris, and which apparently lies inside its disc.
More Embryos Current Events and Embryos News Articles
 | Embryo: A Defense of Human Life by Robert P. George, Christopher Tollefsen The bitter national debates over abortion, euthanasia, and stem cell research have created an unbridgeable gap between religious groups and those who insist that faith-based views have no place in public policy. Religious conservatives are so adamantly opposed to stem cell research in particular that President Bush issued the first veto of his presidency over a bill that would have provided... |
 | The Triumph of the Embryo by Lewis Wolpert Of the great mysteries that face modern biologists, one of the most intriguing concerns the development of the microscopic embryo into exceedingly complex plants and animals--into roses and cacti, elephants and blue whales, apes and human beings. How does one cell give rise to so many millions of cells? How do they divide so as to form hearts, brains, eyes, and ears? Where in this pin-head-sized... |
 | Before You Were Born...Our Wish For A Baby (The Story of Embryo Donation) by Janice Grimes A story book written in age-appropriate, loving language and tells the story of how a child came to be via embryo donation or embryo adoption. The book is written for 3-5 year olds. Using bears as characters, the illustrations depict the typical day in the life of a child interacting with their parent. The story describes a child conceived by in vitro fertilization using the egg and sperm of... |
| Developmental Stages in Human Embryos: Including a Revision of Streeter's Horizons and a Survey of the Carnegie Collection (Publication / Carnegie Institution of Washington) by Ronan O'Rahilly, Fabiola Muller | |
 | Biological Physics of the Developing Embryo by Gabor Forgacs, Stuart A. Newman During development cells and tissues undergo changes in pattern and form that employ a wider range of physical mechanisms than at any other time in an organism's life. This book demonstrates how physics can be used to analyze these biological phenomena. Written to be accessible to both biologists and physicists, major stages and components of the biological development process are introduced and... |
 | The Morality of Embryo Use by Louis M. Guenin Is it permissible to use a human embryo in stem cell research, or in general as a means for benefit of others? Acknowledging each embryo as an object of moral concern, Louis M. Guenin argues that it is morally permissible to decline intrauterine transfer of an embryo formed outside the body, and that from this permission and the duty of beneficence, there follows a consensus justification for... |
 | The Soul of the Embryo: An Enquiry into the Status of the Human Embryo in the Christian Tradition by David Albert Jones A recurring theme in contemporary bioethics is the way in which advances in scientific and medical technology have provoked renewed interest in age-old debates of philosophers and theologians. Nowhere is this clearer than at the beginning of life. In vitro fertilisation, preimplantation diagnosis, therapeutic & reproductive cloning, germ-line genetic therapy, embryo selection and stem cell... |
 | Embryos, Genes and Birth Defects (2nd Edition) The first edition of Embryos, Genes and Birth Defects, edited by the late Peter Thorogood, was a radical new book aimed at bridging the gap between the medical disciplines of embryology and dysmorphology, and recent advances in cellular, molecular and developmental biology. This new edition remains unique in its breadth and brings up to date our understanding of birth defects and of the... |
 | God and the Embryo Discussions and debates over the medical use of stem cells and cloning have always had a religious component. But there are many different religious voices. This anthology on how religious perspectives can inform the difficult issues of stem cell research and human cloning is essential to the discussion. Contributors reflect the spectrum of Christian responses, from liberal Protestant to... |
 | Embryo Culture: Making Babies in the Twenty-first Century by Beth Kohl “Injections + Appointments + Egg Retrieval + Embryo Transfer = Resources (Energy x Time x Emotion)” That’s the equation that was projected onto the screen when Beth Kohl and her husband first showed up at the in vitro fertilization (IVF) clinic. “Good evening,” the program’s psychologist told the gathered infertile couples. “Before you begin your treatment, you should know that... |
| © 2009 BrightSurf.com |