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March 2007 Choosing BabiesA growing number of genetic tests can be performed during in vitro fertilization, before pregnancy even begins. Is that a good thing? By Emily Singer
The following article appears in the March/April 2007 issue of Technology Review. A 38-year-old woman with fertility problems has three sons but wants a daughter to round out the family. She uses in vitro fertilization (IVF) to conceive and asks her doctors to transfer only female embryos; the male embryos are destroyed. Is this use of reproductive technology acceptable? What if a couple with a family history of diabetes wants to use IVF to select an embryo without a particular gene linked to diabetes risk? If afflicted family members largely have the disease under control, are the prospective parents justified in choosing in vitro fertilization so that they can bear a child with a lower chance of developing it at all? Such questions are becoming more common as preimplantation genetic diagnosis (PGD)--testing performed after an egg is fertilized in vitro but before the resulting embryo is transferred to the womb--makes it possible for some prospective parents to select specific embryos before a pregnancy begins. Originally developed more than a decade ago to identify the relatively small number of embryos at high risk for serious or fatal genetic diseases, such as Tay-Sachs, the technology now encompasses genetic tests for a growing number of illnesses, including some that are not necessarily fatal. And these tests are available to more and more parents as the popularity of in vitro fertilization skyrockets; approximately 50,000 babies are born through IVF in the United States every year. All this heightens the ethical concerns that have plagued PGD from the start. As more genes associated with the likelihood of disease are uncovered, the possibility of a truly preventive medicine is within the grasp of many parents. But with that possibility come risks. How well will any one test deliver on its promise of a healthy child? Will parents feel obligated to use genetic testing without adequately understanding its benefits? What kinds of genetic tests will parents want? Recent findings suggest that an increasing number of parents using IVF are choosing embryos according to sex, and it's possible to imagine them one day choosing embryos based on other nonmedical traits, such as hair color, height, or IQ. Preimplantation genetic testing is available only to those who opt for IVF--which now generally means people with fertility problems or a family history of a fatal genetic illness. Though IVF is gaining in popularity, it remains an expensive and often difficult procedure. But the grounds for choosing it are changing: some people, for example, are now using it to select embryos without genes linked to particular cancers--even if the correlation is fairly weak. If parents increasingly choose IVF because it will offer them the opportunity to tailor their children's genetic traits, will the economic division of society become even deeper--separating those who can afford IVF (clinics in the United States generally charge between $6,000 and $16,000) from those who cannot? |
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The Fingerprints of Embryos
05/23/2008
Comments
lkrndu on 03/30/2007 at 5:14 AM
18
But. That is exactly what we will have here, ultimately, with pre-implantation genetic screening, and with genetic testing and pre-selection writ large. Medical testing for gross and severe and fatal defects - Down's syndrome, for example - is the secure corner about which no reasonable person could offer objections. But to insure offspring with nicer dimples?
The ethical tests fail. And will fail, in the onslaught of narcissistic self-fulfillment implicit in now having available - what to call them? - selective services.
Of course there is no bright line separating the extremes. This reader can offer two rough and frail observations, however.
1. If the number of people I have known personally who have suffered or died of genetically-related diseases had been subjected to pre-implantation tests, before they were 'conceived', my world - the world - would be far less interesting. And far less populous. I would go farther: it would be insufferably boring.
That would be a bad thing.
2. Dogs do it. The strongest, smartest, most adaptable are the mutts, while the sleekest, most conforming-to-human fantasy are also the weakest, most freighted with displasias, back problems, nervous disorders, stomachs that get contorted...and all the rest of the sorts of defects that are reinforced through artificial selection that favors the reproducing arbitrarily valued but physiologically and medically irrelevant characteristics.
That's a good thing.
And we should well note and follow that example.
Bob Tyson
karlhedderich on 03/30/2007 at 11:45 AM
9
I agree that when humans start trying to breed organisms for specific traits we often don't account for the whole system. An example of this is tomato breeding/engineering where as the tomatoes have become more uniform in size and color they have lost some of their flavor. The engineers failed to select for all of the traits that were important in a commercial setting. This is a major argument against genetic engineering (or any technology that significantly alters reproductive diversity), how can people determine what traits are "good" traits and how could we select for all of them. This objection to engineering your children seems to be an engineering problem that while significant it isn't intractable. All scientists would have to do is develop the understanding needed so that engineers could make well informed changes. People also argue that suffering leads to greater diversity in the world and while this is true I fail to see how it is a good thing.
gabrielg01 on 03/30/2007 at 4:58 PM
294
Genetic engineering promises to stop such molecular accidents before the person even comes into existence. The technology would work at the sperm or egg level, not at the embryo level.
As for the moral arguments - what would you tell your kid suffering from Huntington's disease? (or other disease - pick your favorite): "You know, we had the technology to prevent this, and give you a healthy life, but we thought that interfering with nature would be immoral..." If this kind of moral argument holds, then we can deny medical treatment for any other disease based on the principle "let nature run its course".
MITBeta on 03/30/2007 at 9:32 AM
21
karlhedderich on 03/30/2007 at 11:47 AM
9
mightybob on 04/01/2007 at 2:38 PM
9
swordfishdata on 04/02/2007 at 8:01 PM
7
Phineas on 04/01/2007 at 2:41 PM
46
Evolution has done a magnificent job but the temptation to alter ourselves will prove too strong. Why propagate bad genes when you have choice? Animal research is applicable to the human animal.The laudable goal will be to improve our lot. Polio today; Huntington's tomorrow.
There are serious potential pitfalls but Folks will fiddle.