The potentially life-saving test being given to newborn babies in Plymouth
Watch Jacquie Bird's report
Derriford Hospital is part of a trial offering expectant mums a test to see if they carry a common bacteria which could put their newborn babies at risk.
Group B Strep causes no harm to mums, but can be dangerous if it is passed on to babies while they are being born.
If it is detected before birth, mums can be given intravenous antibiotics during labour and the birth itself which protects the baby against the bacteria.
It is not routinely tested for on the NHS but this new trial is looking into the benefits of testing to see if it decreases the risk to babies and prevents antibiotics being administered unnecessarily.
Research Midwife Heidi Hollands from University Plymouth Hospitals NHS Trust told ITV News: "There's been a huge debate but the consensus is we need to be testing women to prevent these babies ending up on NICU or ending up really poorly.
"And, conversely, if we are testing women who have had it in a previous pregnancy, but aren't found to be carrying it in the current pregnancy, there is debate about does she need antibiotics? So it may prevent the over-prescribing of antibiotics."
The tests have just started being offered to expectant mums who are over 35 weeks pregnant in Plymouth. Many mums are unaware of the issue.
Expectant mum Natalie Davies said: "We're lucky to live in Plymouth aren't we really? To be able to be in the trial, to be able to get it done. And now I can go into labour knowing whether I've got this or whether I haven't got this, so I'm so grateful to have the test done today."
A total of 320,000 women across the country from 80 different hospitals are taking part in the trial and the results may well change the way all pregnant women are looked after in the future.