Thursday, May 10, 2007

Genetic Testing and Abortion

On the front page of Wednesday's New York Times appeared an article about some potential consequences of the wider availability of low-risk Down Syndrome (DS) screening for pregnant women. Such screening can routinely be made available to women who fall outside of the "over 35" age group whose chances of carrying a DS child are much higher than they are for younger women. The reason that pregnant women under 35 have not ordinarily been screened in the past is that amniocentesis was, for a long time, the only method of testing for the mutation that causes DS, and an amniocentesis carries a risk of miscarriage that -- for younger women whose odds of giving birth to a DS child are exceedingly small -- outweighed the benefits of testing.

Now, however, reasonably accurate screening is possible early in pregnancy by means of two blood tests and an ultrasound examination, each of which is a relatively ordinary and low-risk event for pregnant women in the U.S., regardless of whether or not they are screening for genetic disorders. We know that approximately 90% of the women who learn that they are carrying a DS baby choose to terminate their pregnancies. This suggests that if nearly every pregnant woman screened for DS, the population of individuals with Down Syndrome could fall precipitously.

Many parents of children who have Down Syndrome are quite alarmed at this possibility and say that they do not want their children to live in a world where there are almost no more people like them coming into existence. Such an absence could mean that legislatures would no longer take the interests of people with DS into account. When a condition is rare, the constituency for accommodating those who suffer from it is accordingly small and relatively powerless. To help pregnant women and their families reach different decisions, such parents are therefore opening their homes to people who have received a prenatal diagnosis of DS and showing them that life with a DS child can be a rich and meaningful experience.

I have a few reactions to this story, which -- in the online version -- includes moving testimonials by families with a DS child and footage of such children and the blessings and joy they bring to those around them. My first reaction is empathy. I empathize completely with a parent's desire to have people out there in the world who will fight for the interests of her children and who will form a community into which her children will feel at home and valued. I also respect the fact that parents of children with DS are not all attempting to prohibit abortion but are instead reaching out to pregnant women and genetic counselors in an effort to inform the choices being made.

I do have a competing reaction, however, that is less charitable and empathic than the first. That reaction is to say that a DS child's parents' wish that more DS children be born is a a bit like a parent's wish that other children be sick like her child is. In other words, a parent whose child suffers from heart disease might hope that more children are born with heart disease so that resources are allocated to addressing the needs of sufferers. In a world of scarce medical resources, such a wish is understandable, but it is not one that we would necessarily want to encourage or support. Wouldn't it be better if very few children were born with heart disease?

The matter of genetic screening is, of course, somewhat different from the facts in this example, because a pregnant woman has a specific fetus inside her womb, and that fetus will either live or die. To say that it would be better for her to have a child who does not have DS, then, is not only to recommend preventing a condition but to recommend preventing a particular person from being born. It is, to use a loaded term, a kind of personal "eugenics." And eugenics raises distinct ethical problems, however one views the morality of abortion.

To take the abortion issue out of the equation altogether, consider the following thought experiment. Imagine that scientists develop (as they some day might) a gene therapy that makes it possible to "cure" a baby of Down Syndrome in utero, perhaps by "turning off" the extra chromosome so that it has no effect on the growing human being. If and when such a day comes, I suspect that virtually every pregnant woman who receives a prenatal diagnosis for DS will want to utilize the treatment, even though it will fundamentally alter the "person" who would have emerged into the world absent intervention. Would such tinkering be wrong? Perhaps. Would it represent a loss, to existing DS sufferers, to people who could have loved and enjoyed the company of people with DS and to the world? Absolutely. It is hard not to feel sorrow at this prospect if one has been lucky enough to know a person with DS. But as long as we consider Down Syndrome a disability, one that carries with it special medical needs and hardships and a significantly shorter life expectancy than most of the population enjoys, I am troubled by the aims of a movement whose objective is, explicitly, to increase (or at least prevent a decrease in) the frequency of this condition in the population.