Experts are developing a new way of screening unborn babies for Down's syndrome by doing a simple blood test during the first trimester of the expectant mother. They found out that about 98 percent of cases can be detected using this new non-invasive method.
The results of the study titled "Implementation of maternal blood cell-free DNA testing in early screening for aneuploidies" were published in the journal of Ultrasound in Obstetrics & Gynecology on June 7.
The test analyzed the blood of the pregnant woman and focused on the DNA of the unborn baby present in the blood so chromosomal disorders, known as trisomies, and other disorders can be detected.
At the moment, screening for chromosomal disorders are done using ultrasound and hormonal analysis of the pregnant woman's blood. In case there is a high risk that the woman is carrying a child with a Down's syndrome, the expectant mother is subjected to amniocentiesis and chorionic villus sampling. The tests are quite invasive and present a risk for miscarriage.
The proponents of the study screened 1,005 pregnant women at The Fetal Medicine Centre in London. They implemented blood-cell-free or cfDNA testing to detect trisomies 21 (Down's), 18, and 13 at 10 weeks. On the 12th week of gestation, the researchers also performed ultrasound in addition to cfDNA testing.
The researchers found out that testing during the 10th week of gestation returns lesser false positive results compared when doing the testing on the 11th or 13th week.
"Another major advantage of cfDNA testing is the reporting of results as very high or very low risk, which makes it easier for parents to decide in favor of or against invasive testing," the proponents summarized in their discussion.
"Although most studies were in high-risk pregnancies, we have recently demonstrated that cfDNA testing is applicable not only to pregnancies at high risk for aneuploidies but also to the general population, in which the prevalence of fetal trisomy 21 is much lower[. Consequently, cfDNA testing is far superior to screening methods that are currently in use for these trisomies, and this will lead to widespread uptake of the test in routine clinical practice," the paper stated.
While cfDNA blood test proves to be a less invasive and effective way of telling if the unborn child will have a Down's syndrome or other disorders, it does not really address the problem since the only option for the mothers at the moment is an earlier termination of the pregnancy.
According to Daily Mail, the new blood test to detect Down's syndrome is being tested at the Medway Hospital and Kings College Hospital, both institutions are in the UK.
