A new blood test could warn mothers whether they are at risk of giving premature birth.
About 80 percent of premature births can be pinpointed early on using a test given during the second trimester of pregnancy.
Today women are only assessed at risk if they have already had a premature child or if they experienced complications during labour, the American Journal of Obstetrics and Gynaecology reports.
Those deemed to be at risk are advised to modify their lifestyle by taking lots of rest and can be given hormones that help keep the baby in the womb for longer, according to the Daily Mail.
US researchers have discovered three new peptides - complex compounds found in many forms in the body - in the blood of eight out of 10 women who went on to have premature births.
Researchers tested blood samples from 160 pregnant women between 24 and 28 weeks, half of whom went on to give birth early. The blood test has been patented in the US and it is due to go on sale there next year.
Said Sean Esplin, obstetrician and professor of maternal-foetal medicine at the University of Utah, who led the study: "With pre-term birth, if we could even prolong a pregnancy by one or two weeks, we could make a very big impact on the number of babies that survive and make sure that those that survive are healthy."