An 8-year study of nearly 40,000 women showed that Down Syndrome can be detected in the first trimester, as early as 11 weeks into a pregnancy, using a combination test of ultrasound and blood-protein testing.
This new testing method has a higher initial detection rate (87% vs 81%) than the current standard quadruple test, which happens at 16 weeks. When combined, the two tests had a 95% detection rate and a quite high 5% false positive rate. But just as a positive result on the quadruple test often spurs an amnio for confirmation, the nuchal translucency test can be followed up with a chorionic villus sampling (CVS). Both of these follow-up tests carry some risks, though.
I think when we were deciding whether to go ahead with the quadruple, we talked about doing whatever we could to be prepared, as long as it didn't present risks for the kid. Since for us, the amnio would have only served as confirmation of our need to prepare for a Down's kid, we talked about being prepared to go through the pregnancy with the possibility of a false positive rather than put the kid at some risk for our own confirmations. It's the understatement of the century to say that your results may vary. What's important is that they're your results. [thanks to dt reader Elaine for catching a crucial data error in a previous version of this post.]
Down Syndrome Now Detectable In 1st Trimester [wash post via tmn]
Previously: Wash. Post Down Syndrome/Abortion Editorial Fracas