Currently, pregnant women are offered a screen test for Down Syndrome during the first trimester of pregnancy. Although the test, the nuchal fold or nuchal translucency test, is a simple ultrasound, it does have a relatively high false positive rate. A woman whose nuchal fold test indicates a risk for Down Syndrome is offered either an amniocentesis or chorionic villi sampling, which involve inserting a needle into the uterus. There is a risk of miscarriage associated with both of these invasive tests.
However, according to this article, researchers from London have developed a new blood test with a much higher sensitivity than the nuchal fold test. With the new test, only one in every 1,000 women tested is likely to be offered a more invasive test like an amnio or a CVS. In comparison, as many as 50 women out of 1,000 are candidates for amnio or CVS after nuchal fold testing.
Not only are families more likely to get more accurate results for Down Syndrome risk, they are much less likely to require an unnecessary invasive test that could cause miscarriage.
So far the test is being offered in one chain of US clinics at a cost of $700.
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