April 21, 2024

New Down syndrome test could be more “efficient”

UK researchers are hailing the development of a ‘safer’ and more ‘cost-effective’ pregnancy-screening test.

UK researchers are hailing the development of a “safer” and more “cost-effective” test for Down syndrome. The newly developed procedure, which involves screening the blood of a mother for foetal DNA, is a far less invasive alternative to the current procedure (amniocentesis) used to detect Down’s syndrome.

The new method was recently trialled on 2500 expectant mothers at Grand Ormond Street Hospital in London, and researchers say it is both less risky and cheaper.  

The current method, amniocentesis, involves the sampling of amniotic fluid obtained through the insertion of a hollow needle into a mother’s uterus. This procedure significantly increases the chance of a miscarriage, aside from being quite frightening and often painful for pregnant women.

The new procedure involves one simple blood test. “Instead of taking an invasive sample, we can take a sample of the mother’s blood, and we can look at the levels of DNA in mum’s blood and, if there’s a little bit more chromosome 21 than we expect, that will be an indication that he baby has Down’s syndrome”, explained Lucy Jenkins, director of Genetics at Great Ormand Street Hospital.

The test does not, however, totally eliminate the need for amniocentesis. Mothers who ‘test positive’ on the blood test still need to undergo amniocentesis for confirmation.

“We have approached women to be involved in this study who maybe have a more moderate risk associated with Down’s syndrome, so there are women having access to the test who wouldn’t previously have had,” Dr. Jenkins said.

“Also, women who would never consider having an invasive test, maybe would access this test because it’s less invasive.”

Disability rights groups are concerned that the new test will increase the number of disabled children being aborted.

But experts claim this will not necessarily happen. “It may offer parents more choices, but I don’t think all of those parents are necessarily going to choose to terminate the pregnancy”, said UCL Professor and trial co-ordinator Lyn Chitty. 

Doctors develop new pregnancy screening test for downs syndrome
Xavier Symons
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Down syndrome