Great Ormond Street Hospital in the capital is to trial a new test for Downs' Syndrome to see if it should be offered to pregnant women by the NHS.
Non-invasive prenatal testing (NIPT) can predict with 99% accuracy whether a baby has Down's but is currently only available in private hospitals.
The blood test detects a baby's genetic material and does not carry any risk of miscarriage like current invasive tests.
At present, testing for Down's involves a combination of an ultrasound scan of the baby and a blood test for the mother.
Experts then estimate a woman's chance of having a baby with Down's.
Those found to be at higher risk can opt for further tests, such as amniocentesis -but this carries a one in 100 risk of miscarriage.
The new test also screens for the rare genetic conditions Edward's syndrome and Patau syndrome.
More top news
It's being called London's first modern contemporary art walk. And it begins today.
Police are attempting to find a vulnerable missing 16-year-old girl who is feared to be with a 51-year-old man.
The owners of two Hackney bakeries have had to pay £28,000 after infestations of cockroaches and mice were found on the premises.