Making a DNA test for Down’s syndrome available on the NHS would reduce the dependency on invasive tests and potentially save the lives of unborn babies, a UK study suggests.
Cell-free DNA testing involves a far less-invasive blood test and is a highly reliable test for Down’s syndrome, noted lead study author Professor Kypros Nicolaides, from King’s College Hospital and King’s College London.
However, it is currently only available privately and costs hundreds of pounds.
“Our research puts the case for offering the cell-free DNA test on the NHS”
At present, risk of carrying a baby with Down’s syndrome is based on age, hormone levels and a “nuchal scan” of fluid collection at the unborn baby’s neck.
Women deemed to be high risk following this “combined assessment” are given the option of further tests, which involve chorionic villous sampling or amniocentesis.
Both methods are still the only tests that can provide a definitive diagnosis of Down’s syndrome, but carry a risk of miscarriage.
The new study involved 11,692 women with single pregnancies treated at two different hospitals – King’s College Hospital in London and the Medway Maritime Hospital in Kent.
A small proportion of these women (395) were found to be at high-risk for Down’s syndrome.
The results of the study suggested that the best approach to screening for Down’s syndrome was to offer the combined test to all pregnant women and, based on the results, to select a group that would benefit from the cell-free DNA test.
The study also found that the DNA test could be easily incorporated into routine clinical care within the NHS, and was the preferred option for pregnant women.
In this way, the researchers said a higher proportion of affected pregnancies can be identified, resulting in a small increase in the overall cost to the NHS, but a major decrease in invasive tests.
Professor Nicolaides, director of the Harris Birthright Research Centre for Fetal Medicine at King’s, said: “Our research puts the case for offering the cell-free DNA test on the NHS.
“This would improve the performance of screening, and reduce the number of unnecessary invasive tests and miscarriages,” he added.
The study results have been published in the journal Ultrasound in Obstetrics and Gynaecology.