Novo teste de screening genético levanta novas questões éticas

Nova tecnologia envolve a habilidade de mapear células fetais no sangue da mulher gravida, permitindo assim a detecção precoce de doenças genéticas do feto, a partir da 7 ou 8 semana de gestação. Esta técnica viria a substituir a aminiocentese. Com isso já há um decréscimo de nascimentos de crianças com Síndrome de Down em países que já adotam a nova tecnologia. Hi. I am Art Caplan at the New York University Langone Medical Center Division of Medical Ethics. Today I want to discuss an interesting ethical challenge that is emerging from a technological innovation in the area of genetic screening. Historically, a pregnant woman who was deemed at risk of having a child with a severe birth defect would have undergone genetic testing using a technique called amniocentesis. Many of you know that this involves putting a needle into the pregnant woman's belly and pulling amniotic fluid out so that you can get cells from the fetus and analyze their genetic composition, looking for abnormalities such as Down syndrome. That test can only be performed when the fetus is large enough to be sloughing off cells. Inserting the needle into the womb poses some risk of harm to the fetus if the needle accidently nicks it, or rarely by causing an abortion. There are also dangers of infection for the mom. But for women over age 35, the potential of having a child with a severe congenital defect has been deemed large enough to justify taking those risks. That technique is soon to be in the dustbin of history because we have a new technology just emerging that I think is going to push it away forever. That new technology involves the ability to draw cells from the pregnant mother's blood and find fetal cells circulating inside the mother's bloodstream. If you can get those cells out and then copy them or clone them, you can perform the same type of genetic tests that you can do with amniocentesis, but with no risk to the fetus. There is no needle injected into the womb. You are just taking a blood sample and analyzing the fetal cells that way. So...What's the Ethics Problem? This is clearly going to be a technique that replaces amniocentesis, so what is the ethical problem? Isn't this a technology that is all to the good? No more needles, no more risk to mom, no more infections, and so on. Unfortunately, there are some potential ethical problems. Amniocentesis is a test performed on perhaps 5% of pregnancies. The ability to draw cells from the mom's blood will quickly become a test that is used on 100% of pregnant women. I would be surprised if it does not become the standard of care. More testing means that more women may find problems with their fetuses. This test can be performed much earlier than amniocentesis, possibly enabling fetal screening at 7 to 9 weeks. Many people worry that this will lead to more pregnancy terminations. Women who would not have had testing before this will undergo testing, and some may discover things about their fetus that they will not accept, be it a birth defect or some other disease risk factor. Because it is earlier, the burden of abortion may seem morally more acceptable to women than having an abortion much later in pregnancy. Thus, while this technology brings much that is good -- earlier and less risky fetal cell screening -- it certainly will wind up being controversial. If it leads to more abortions, many critics will say that it is not a good thing. It is something we have to try to restrict. Conversely, if it is easy to do, many doctors will say this must be done routinely for everyone, and it quickly will become the standard of care. But that means much more counseling and much more discussion of the findings. It is one thing to find Down syndrome and decide what to do early in the first trimester of pregnancy. It is another thing to find that your baby has a high risk for breast cancer when they get to be 50 years old. Is that a reason to terminate a pregnancy? I believe we will have many ethical discussions about this rapidly evolving technique of fetal cell screening using blood tests. The good news is that it is safer, more efficient, and less burdensome to the fetus and mom than amniocentesis. Perhaps the bad news is that it will result in a lot more ethical arguments and discussions about the rationale for ending a pregnancy, what constitutes a disability, and who is going to do the counseling with women who previously have never had fetal testing during their pregnancies. I am Art Caplan at the NYU Langone Medical Center. Thanks for watching.