A group of NHS hospitals in London are in discussions to use a new non-invasive prenatal test for Down’s Syndrome that has been proven to be more accurate than other forms of testing for the condition.
The non-invasive prenatal test (NIPT), which involves taking blood from the mother, is around 99% accurate in detecting whether the baby is likely to have the condition.
“This test offers expectant mothers greater accuracy in detecting Down’s Syndrome and reduces the anxiety… associated with an invasive test”
Conventional “combined tests” offered by the NHS, involving an ultrasound scan and blood test to calculate the risk of Down’s Syndrome, have an accuracy rate of between 84% and 90%.
The NIPT allows the baby’s genetic profile to be screened from the blood sample, due to a recent discovery that a developing foetus’ DNA circulates in its mother’s blood.
The improved accuracy, compared to the traditional testing, means it is less likely that mothers will be wrongly diagnosed as carrying a child with a high risk of developing Down’s Syndrome.
“We are delighted to be the first laboratory in the country to offer this service to NHS hospitals”
This means the NIPT is also safer because in high risk cases, mothers are currently required to go on to have an invasive test to confirm whether the baby has Down’s Syndrome. This involves putting a needle into the womb, a procedure which has a 0.5% chance of causing a miscarriage.
NIPT analysis is being offered to a “handful” of hospital maternity units in the North Thames region by Great Ormond Street Hospital Foundation Trust, which developed the test at its laboratory.
It is expected that the test will be provided by trusts in addition to the conventional combined testing carried out by the NHS as standard.
Lucy Jenkins is interim director of the North East Thames Regional Genetics Service Laboratory at Great Ormond Street, which is only NHS laboratory in the UK with the ability to carry out NIPT analysis.
She said: “This test offers expectant mothers greater accuracy in detecting Down’s Syndrome and reduces the anxiety and risk associated with an invasive test.
“As with all prenatal testing, the NIPT is about providing women and their partners with knowledge and choices, and we are delighted to be the first laboratory in the country to offer this service to NHS hospitals,” she said.
A trial of the NIPT was completed in February as part of a study funded by the National Institute for Health Research looking into the effectiveness of its use within the NHS.
The results of this study will be available later in 2015 and will be submitted to the UK National Screening Committee, the body which sets the standards for antenatal screening in the NHS.