Blood test for Down’s set to be offered on the NHS
A SIMPLE blood test for Down’s syndrome is to be offered to pregnant women on the NHS.
Currently, mothers-to-be are offered an invasive amniocentesis test – which carries a small risk of triggering a miscarriage – but thousands of women refuse to take it.
The UK National Screening Committee yesterday recommended that the new test, which is 99 per cent accurate, should be made available in hospitals.
Public health minister Jane Ellison is expected to approve the advice in the coming months, with the test then made available to women at risk of having a child with Down’s.
All pregnant women are currently offered an ultrasound to measure the amount of fluid at the back of the baby’s neck at 11 weeks, as well as a basic blood test that picks up broad genetic traits.
Under present guidelines, women whose tests show a high risk of giving birth to a Down’s baby are then offered the amniocentesis test, in which a long needle takes a sample of the placenta.
The invasive test is very accurate, but for one in every 200 patients it causes a miscarriage, and in some cases even healthy babies are lost. A trial at Great Ormond Street Hospital found that the threat of a miscarriage put women off from taking the amniocentesis test, with only 65 per cent agreeing to take the test.
When they were offered the new, non-invasive test, the take-up rose to 95 per cent.
The new blood test – which will be offered to women who have already had the ultrasound – carries no increased danger of miscarriage. It works by picking up fragments of the child’s DNA that have passed into the mother’s bloodstream, and picks up the risk of a child being born with Down’s, Patau’s or Edwards’ syndromes.
The examination – called a noninvasive prenatal test (NIPT) – is made by UK firm Premaitha Health. It is already available privately, at a cost of up to £400, but although it has been piloted at Great Ormond Street and St George’s Hospital, both in London, it has never been widely offered as a matter of course.
Labour MP Tulip Siddiq, who is expecting her first child, this month announced that she had to pay £400 to take the test, and warned that those who could not afford it might be forced to take the riskier alternative.
‘The non-invasive test should be rolled out across the country so that mothers, regardless of wealth, can have equal access to screening and do not have to face the unnecessary risk of miscarriage,’ she told the House of Commons.
It is not clear how much the new test will cost the NHS, but it is likely to be substantially less than the cost to private patients. The blood test is understood to be cheaper than the amniocentesis test.
In the new recommendations, government advisers say women found in the initial combined test to have a one in 150 or greater chance of having a baby with Down’s should then be offered the NIPT test.
Professor Lyn Chitty, who led the Great Ormond Street trial, said last night: ‘Introducing NIPT into NHS maternity care means that more women can be safely reassured about the health of their baby without having an invasive test which increases the risk of miscarriage.’
Down’s syndrome, which affects one in every 1,000 babies in the UK, is a genetic condition caused by an extra chromosome in the body’s cells. The condition causes learning disabilities and other problems, but many go on to live full lives, with an average life expectancy of between 50 and 60.
A Department of Health spokesman said: ‘We welcome these important recommendations from the UK National Screening Committee, which have the potential to transform antenatal screening.
‘We are now considering the recommendations.’