New DNA test could revolutionize prenatal screening
NEW YORK -- A report in the New England Journal of Medicine Wednesday could revolutionize prenatal screening for Down Syndrome and other disorders.
When 29-year-old Jennifer Fontaine was pregnant last year, a standard blood screen suggested her baby had a severe genetic defect.
But that standard blood screen isn't definitive and has a high rate of false positive results.
So Fontaine was given the option of either an amniocentesis -- an invasive test that carries a 1 in 600 chance of miscarriage -- or a more targeted blood test which analyzes fetal DNA circulating in the mother's blood. She opted for the blood test.
After waiting for more than two weeks, she got good news; there was no defect.
"It was the best feeling ever to know everything was fine and that in a few months we were going to have a perfect baby little girl, so we were happy," said Fontaine.
That's a tenfold reduction in false positives.
Dr. Diana Bianchi of Tufts Medical Center led the study.
"Far fewer women are made anxious and need to go on to the further counseling and certainly there's a reduction in the need for an invasive diagnostic procedure," said Bianchi.
The DNA test costs as much as $1,500, but given the potential benefits of avoiding further invasive testing, that might change.