If earlier screening results in fewer babies with Downs syndrome, is that a good thing?

    A new prenatal test, safer and easier than established methods, has one geneticist asking if babies with Down syndrome will gradually disappear, and if that’s a good thing. What do you think?

    A new first-trimester blood test that can detect whether a fetus has Down syndrome is less invasive than traditional forms of prenatal testing such as amniocentesis and chorionic villus sampling (CVS) and, unlike those tests, carries no risk of miscarriage.

    As the test becomes more widely available, it could save lives by preventing miscarriages, but some ethicists speculate that it could result in more terminated pregnancies. Already the rate of women who choose to terminate a pregnancy when they receive a prenatal diagnosis of Down syndrome is 92 percent or more.

    Is informed consent enough?

    WHYY’s Taunya English reported on the new test, going by the brand names Harmony and MaterniT21, and some concerns in the medical community. (T21 refers to the abnormality of chromosome 21 that causes Down syndrome in one out of 691 American pregnancies, called “trisomy,” which occurs when there are three copies instead of the expected two.)

    In the report, Deborah Driscoll, an obstetrician-gynecologist and geneticist at the University of Pennsylvania, makes the point that geneticists and ethicists want to be sure that women give informed consent for the new test. “Every physician or counselor that offers this explains to the patient what the test is for, what are the limitations for the test, and what it can potentially disclose,” she said.

    But Dr. Brian Skotko, a Children’s Hospital of Boston clinical genetics fellow, has been saying that women need more than that for fully informed consent. Women are given a lot of information during their pregnancies that can lead to some brutally difficult decisions. Without knowing more about what life is really like for families to raise a child with Down syndrome, he and other researchers says, women could be making decisions based on misconceptions.

    Quality of life

    Skotko gives some statistics on his blog from research published in the American Journal of Medical Genetics:

    99% of people with Down syndrome said they were happy with their lives
    97% of people with Down syndrome liked who they are
    5% of parents felt embarrassed by their child

    About 400,000 Americans have Down syndrome, the most common genetic condition in the United States

    Skotko’s research suggests that without prenatal testing in the United States, there would have been a 34 percent increase in the number babies born with Down syndrome between 1989 and 2005. But 15 percent fewer were born during that time — a 49 percentage point difference from the expected rate.

    Will babies with Down syndrome slowly disappear?” Skotko asks.

    To take it further, what other characteristics should expectant parents be able to select against — sex, propensity for disease, sexual orientation? What information do parents have the right to know?

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