New Screening for Down Syndrome Reduces Risk of Fetal Injury and MiscarriageMeredith Carroll
To what will likely be the relief of thousands of pregnant women, a study published this week in the Journal of British Medicine said that technology developed in Hong Kong in 2008 has resulted in a new pre-natal screening for Down syndrome that produces more accurate results with fewer risks than the current methods available.
The current screenings for Down syndrome, the most common genetic condition in the United States in which those afflicted have three copies of chromosome 21, generally come with risks to the fetus because of the invasive nature of the procedures.
An amniocentesis, which is generally performed at 18 weeks gestation, is when a needle is inserted into the uterus to extract amniotic fluid. Fetal injury or miscarriage can occur in 1 out of 200 patients. The Chorionic villus (CVS) test, which can be done at 10 to 13 week, is when a placental tissue sample is extracted. In that case, the risk of fetal injury or miscarriage is 1 in 100, and there is also a chance of false positive results, according to ABC News.
The new procedure, which is being called a breakthrough, is a maternal blood test in which the fetus’ genome is studied through the mother’s plasma — whereby abnormalities in the 21st chromosome can be searched for and detected — and has the potential to cut down on women who undergo CVS testing, an amniocentesis or other safer but less accurate tests by 98 percent. The hope is that as the technology advances even further, pregnant women can be tested in the first trimester for Down syndrome through this blood test without any danger to their pregnancy.
“We are saving babies,” Dr. Rossa Chiu, first author of the study and a clinical chemist at The Chinese Universirty of Hong Kong, told ABC News. “And just because we know the results doesn’t mean women have to terminate. We are saving women from losing normal children just because of a procedure.”
The new test is meant to supplement the screening methods currently available, at least until the new technology with 100 percent detection is perfected, according to the new findings.
At the moment the test is not available in the United States, as labs need to be upgraded to handle the more sophisticated equipment, plus, the $2,000 price tag is prohibitive. But the belief is that the cost will come down within a year and the tests will start to become offered.
The news of a less invasive, less risky test has to come as a relief to so many women who forgo the CVS test and/or an amniocentesis precisely for the small but very real dangers involved. Women go through a roller coaster of emotions and testing over the course their pregnancies, and to be on the verge of taking away one of the most stressful elements — the hazards associated with genetic testing — by removing the actual risks seems to be not only a breakthrough, but a real gift.
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