Down syndrome is the most commonly occurring chromosomal condition. In the United States, one in every 691 babies born has this chromosomal abnormality, says the National Down Syndrome Society (NDSS). Recently, a team of United States researchers has discovered that a new blood test among younger and low risk women shows promise in the detection of Down syndrome than other standard prenatal tests.
They announced their discovery on Wednesday and said that they are ready for widespread use of the said test. Meanwhile, Great Ormond Street Hospital has already started using a similar test for Down syndrome.
The study, which was published in the New England Journal of Medicine, is the largest study to show that tests are indeed accurate even in low-risk pregnant women. However, they recommend that even if a woman incurs a positive result, they should still undergo confirmatory testing through more invasive diagnostic testing like amniocentesis.
"This is a great test for detecting Down syndrome but it doesn't detect everything, it isn't diagnostic, and it doesn't always work to provide a result," explained Dr. Mary Norton of the University of California, San Francisco as reported by Reuters.
The researchers now recommend that blood tests will be able to replace all current tests for all women regardless whether they are high risk or not. To land to their findings, they were able to correctly identified 38 cases of Down syndrome out of nearly 16,000 women tested, BBC News reports.
But there were still nine false positive results in the group that got cell free fetal DNA screening.
According to past data, around one million fetal DNA tests have been performed since 2011 and one consequence is that once women receive a negative result, they opt out of invasive testing resulting in miscarriage. Furthermore, the new tests presented were not regulated by the Food and Drug Administration. Thus, their results could mislead patients.
According to Ankita Patel and colleagues from Baylor College of Medicine and the Chinese University of Hong Kong, in a letter published in the same journal, the information women receive from these tests should not make them decide to terminate pregnancies. They should opt to go for further tests which would confirm the condition.
This is based on their research based on 307 women who tested positive on fetal DNA tests and it included around 57 false positives.
