"A new blood https test may help pregnant https women who are at high risk for having a baby https with Down syndrome https avoid more invasive tests such as amniocentesis https and chronic villus sampling CVS. The blood https test analyzes components of genetic material from both the pregnant woman and her fetus https that is present in the mothers blood. It could help avoid up to  of these screening procedures according to the study which appears in BMJ. While amniocentesis https and CVS can help definitively determine if an unborn baby has Down syndrome or trisomy  these tests do carry a risk of miscarriage https and some women are unwilling to take this risk. These tests also screen for other less common fetal abnormalities and birth defects https such as trisomy  and trisomy  https Accuracy of Blood Test The new blood test would be used if a woman was considered at high risk for having a child with Down syndrome based on her age or other factors. The sequencing test could be used to rule out trisomy  among highrisk pregnancies before proceeding to invasive diagnostic testing to reduce the number of cases requiring amniocentesis or CVS conclude study authors who were led by Dennis Lo of the Chinese University of Hong Kong in China. The new study included  pregnant women who were at high risk for having a child with Down syndrome. Of these  women were determined to be pregnant with a child with Down syndrome. There were no falsenegative results with the new test suggesting it can help avoid  of followup invasive tests in women whose test shows that their baby does not have Down syndrome. In a year or two this test may be available but it wont replace existing technologies it will nudge its way into our armamentarium of available methodologies says Mark I. Evans MD director of Comprehensive Genetics in New York City and an obstetrician https at Mount Sinai School of Medicine also in New York City. Not Ready for Prime Time The bad news is that prenatal diagnosis is not just about Down syndrome he says. Down syndrome represents about  of what we find and this new test can help with that but it may also give women a false sense of reassurance. Still he adds its an important step forward. The technology is likely prohibitively expensive and timeconsuming at this point he says. Its not ready for prime time but researchers are actively working on methods to increase its efficiency he says. Patients are very concerned about loss rates with aminocentesis and CVS and want reassurance about their pregnancies so we are always looking for a better test says Jennifer Wu an obstetriciangynecologist Lenox Hill Hospital in New York City. This test looks very promising but it is also very expensive  While there are risks attached to amniocentesis and CVS screens these are minimized when the test is performed by a skilled obstetrician she says. The new test looks very promising says Cathy Sullivan a genetic counselor at the University of Texas Health Sciences Center in Houston. We are not quite there yet but it may become a real possibility for finding out real information without having to risk a pregnancy. For example If this comes back negative you dont need an amniocentesis but if it comes back positive we would probably still do an amniocentesis to confirm the results she says. While the new screen only looks for Down syndrome Sullivan says that some of the other trisomy birth defects can be more easily identified on an ultrasound https exam. Many babies with Down syndrome appear normal on an ultrasound she says. Joyce Fox MD the chief of medical genetics at Cohen Childrens Medical Center in New Hyde Park N.Y. definitely sees a role for a test such as the one described in the new study. For now the test just looks for Down syndrome but technology will advance to the point where noninvasive testing will encompass more of the less common genetic anomalies she says. For women who are concerned about losing a pregnancy as a result of an invasive test this is an excellent addition to our armamentarium of screening she says. It is not a diagnostic test for Down syndrome she says. It can help women put some of the information from other tests into context."