Researchers in the UK have tested a new screening scheme for Down syndrome and other chromosomal disorders, Reuters reports.
In this reflex DNA screening approach, pregnant women still undergo conventional ultrasound and a finger prick blood testing for chromosomal disorders, Reuters says, but they also give an additional blood sample at the time that's set aside. If those initial, conventional tests indicate that the woman is at high-risk for trisomy 21, trisomy 18, or trisomy 13, that blood sample is then used for DNA analysis. Only if that, too, indicates a chromosomal abnormality does the woman return for a more invasive diagnostic test, according to Reuters.
In a recent study, researchers at maternity hospital in the UK found that this approach could limit the number of women who undergo such invasive testing when they don't need to. Queen Mary University of London's Nicholas Ward and his colleagues reported in Genetics in Medicine last month that this approach avoided up to 530 invasive diagnostic tests in their cohort of 22,812 women.
"In the reflex DNA method, most women undergoing an invasive test will have an affected pregnancy," Wald tells Reuters.