Fetal DNA testing can discover disorders better and more accurately according to a new study. Fetal abnormalities can be screened with DNA testing, however, experts warn that the test has not been proven effective in rigorous clinical trials.
A study published in the New England Journal of Medicine stated that fetal DNA testing has been proven to be a reliable source in discovering abnormalities in DNA sequencing that result in disorders like Down syndrome. Making up to 20 percent of the total DNA in a pregnant woman, fetal DNA segments come from the placenta. Using fetal testing by Illumina Inc., the DNA test is able to detect the unusual three copies of a chromosome when their should only be two.
The Illumina method, known as verfi, simply counts the fragments that are associated with chromosome attributed disorders. If the test shows any abnormalities, the patient is informed by the doctor and they proceed to a sampling from the amniotic sack. During this time, the doctor, assisting with an ultrasound scanner, places a hypodermic needle into the uterus and extracts amniotic fluid. The doctor also takes a catheter needle to extract a small sample of tissue to determine the health of the unborn child.
While many doctors are in support of this new and more efficient way of testing, the American Congress of Obstetricians and Gynecologists says there is not enough evidence at this time to endorse the tests as screening tools for low-risk women. Seeking to address those concerns, Dr. Diana Bianchi of Mother Infant Research Institute at Tufts Medical Center and her colleagues conducted a study using 1,914 low-risk pregnant women. The result was overwhelmingly positive as the fetal DNA test for Down syndrome had a significantly low false-positive rate of 0.3 percent.
While initial tests indicate that the Illumina test could be used for screenings, more studies will be done before it becomes the medical standard.
Study Says Fetal DNA Testing at Illumina Discovers Disorders Better.