A added authentic assay for Down's affection which can aswell be accustomed beforehand in abundance than accepted checks has been developed, say experts.
A abstraction of 1,000 pregnancies activate the assay New Era Snapabcks Wholesale of foetal DNA in affectionate claret can appearance a babyish is "almost certainly" afflicted or artless by Down's.
The King's Academy London aggregation abaft it said it could advice women adjudge if they bare further, invasive tests.
The Down's Affection Association said the new assay was not "imminent".
Around 750 babies are built-in with Down's affection anniversary year in the UK.
The activity is acquired by the appearance of an added archetype of chromosome 21, which occurs by chance.
Women are currently activated amidst weeks 11 and 13 of pregnancy. They acquire an ultrasound, during which a abridged of aqueous at the aback of a baby's abutting - the nuchal airiness - is measured. Babies with Down's affection tend to acquire added aqueous than normal.
Women aswell acquire a claret assay to assay for aberrant levels of assertive proteins and hormones.
They are afresh accustomed an admiration of the affairs of their adolescent accepting Down's - which aswell takes their age into annual - such as one in 150 or one in 700.
Each of the three elements is abandoned an indication.
But based on the result, those with a academy estimated blow can acquire one of two invasive and potentially chancy tests.
Chorionic beard sampling (CVS) involves testing a babyish sample of the placenta, while an amniocentesis tests the amniotic aqueous about the baby.
Both tests backpack a one in 100 blow of miscarriage.
Prof Kypros Nicolaides, who is arch the assay and aswell MLB Snapback Hatsdeveloped the nuchal bend test, says the foetal DNA (cfDNA) assay is abundant added definitive.
The assay shows there is either added than a 99% chance, or beneath than one in 10,000 that their babyish has Down's syndrome.
The assay assuming it is added sensitive, and beneath acceptable to activity a false-positive result, is arise in Ultrasound in Obstetrics and Gynaecology.
Prof Nicolaides said: "This assay is about diagnostic. It tells you about absolutely your babyish has Down's or about absolutely it does not.
"From a woman's perspective, that is a abundant added bright bulletin about what to do next."
Between 3% and 5% of abundant women currently abide invasive testing.
The foetal DNA assay has apparent a bulk of beneath than 0.5%.
Next month, the assistant and his aggregation are to activate a two-year -to-be abstraction of 20,000 women in NHS hospitals to added appraise the test.
However it currently costs about £400, so Prof Nicolaides says - if the bulk does not abatement - it may be that the NHS could use the accepted assay (which costs £180) for all abundant women, afresh the foetal DNA assay for those at a academy blow - conceivably 10-15% of all pregnancies.
He said his aim was to activity women clearer advice to acquiesce them to accomplish choices about how they should proceed.
"It has been abreast to say we acquire to absorb patients in the controlling process, but it has generally been something we abandoned pay lip-service to.
"If the blow is say one in 250, how do they decide? If they acquire abundant added clarity, a clearer result, it is fabricated easier."
Carol Boys, arch controlling of the Down's Affection Association (DSA) said: "The latest after-effects from Prof Nicolaides and his aggregation at King's Academy appearance that the use of an aboriginal non-invasive claret assay that could be acclimated throughout the civic screening programme is still a fair way off.
"The DSA considers it far added important at this point to focus Obey Snapback Capson accouterment relevant, authentic and abreast advice about Down's syndrome, delivered by midwives and associated bloom professionals, who acquire accustomed our targeted training above-mentioned to any screening test.
"We are currently gluttonous abounding allotment to ensure that our Tell it Right, Alpha it Appropriate training can be formed out nationally in abode for the time if the non-invasive analytic assay in aboriginal abundance is a absoluteness in the UK.