Progress Toward Blood Test for Down Syndrome
Study Shows Blood Test May Allow Pregnant Women to Avoid Invasive Prenatal Screening Tests
‘Not Ready for Prime Time’ continued...
Still, he adds, “it’s an important step forward.”
The technology is likely prohibitively expensive and time-consuming at this point, he says.
“It’s 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 obstetrician/gynecologist 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 don’t 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 exam.
“Many babies with Down syndrome appear normal on an ultrasound,” she says.
Joyce Fox, MD, the chief of medical genetics at Cohen Children's 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.