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
Leading vet charity PDSA's Pet Survivor competition reveals stories of miracle survival.
Most of the city shuts down but there is still plenty to do in Central London on Christmas Day.
The victim reported Samantha Watt to police in July after she discovered the photos had been put up on her Facebook page.