Pregnant women can be screened for infections which might help prevent premature births, say US scientists.
Testing for infections may reduce the rate of premature births
In the UK about 8% of babies are born prematurely, before 37 rather than the usual 40 weeks of gestation.
Infection involving the sack around the baby in the womb can trigger early delivery.
A simple test detects these infections say US researchers at Oregon Health & Science University in the Journal of the American Medical Association.
Early testing for infections followed by treatment where necessary could prevent numerous premature births, Dr Michael Gravett and his colleagues believe.
The test measures patterns of protein markers in amniotic fluid - the fluid that cushions the baby while inside the womb.
If an infection is present, the pattern looks different from that of healthy amniotic fluid.
Co-researcher Dr Srinivasa Nagalla said: "The likely outcome of this finding is that a simple test may be developed to detect the presence of these biomarkers, thereby signalling the pregnant woman has an infection that needs treatment."
The researchers first tested the device in primates and found 11 markers of infection.
When they tested pregnant women with known infections, the same 11 markers were present.
The test was accurate and did not detect infection when none was present.
"Biomarkers for infection were detected in a very short amount of time, within only 12 hours of infection," said Dr Nagalla.
Dr Gravett said: "By finding a method for quickly detecting one of the major causes of preterm labour and then treating it, we believe this finding could have a very significant impact and save young lives."
A spokeswoman from the premature baby charity BLISS said: "If women at risk of a premature birth due to infection can be identified, that's really good news.
"In the UK, around 8% of babies are born prematurely, that's about 45,000 babies, and if a way can be found to reduce this number, it will have a major impact in reducing the number of babies dying and those needing neonatal intensive care.
"However, more research will be needed to identify how and when the test should be used.
"Whether our health service would be able to fund the routine use for such a test for all pregnant women is also open for debate," she said.