Experts hail accurate new DNA test for Down's

A BLOOD test to check for Down's syndrome could almost eliminate the need for invasive procedures, new research suggests.

The highly accurate test looks at the genetic material DNA to predict whether a woman is carrying a baby with the syndrome.

Current testing on the NHS combines a blood test to check levels of some proteins and hormones with a scan to measure the space between the spine and the nape of the baby's neck. Babies with Down's syndrome tend to have more fluid collecting in the neck than those developing normally.

The "false positive" rate of these tests is about 5 per cent. Women told they may be expecting a Down's baby are then offered the option of further, invasive tests, including amniocentesis or chorionic villus sampling, which have about a 1 per cent risk of miscarriage.

If these women were given the DNA blood test instead, almost all invasive procedures could be avoided, according to experts from Hong Kong, writing in the British Medical Journal.

They wrote: "If we took into consideration the results of the sequencing test, trisomy 21 (Down's] could be ruled out in 98 per cent of those pregnancies.

"This would leave just 0.1 per cent of all pregnant women needing referrals for amnio-centesis or chorionic villus sampling."