Researchers from the University of Gutenberg, Sweden, studied 142 pregnant women who came to Sahlgrenska University Hospital during the years 1995-2005 with early contractions without rupture of the membranes.
Delivery before 37 full weeks, so-called preterm delivery, is the biggest problem in perinatal medicine today, as it increases the risk of the child being seriously ill in the short and long term.
The problem is that only 30 per cent of women who come in with early contractions actually give birth before full term.
The new method is based on a blood test that looks at two specific proteins in the woman's blood combined with an already established examination that uses ultrasound to measure the length of the cervix.
"Statistically, the method can predict with 75 to 80 per cent accuracy if a woman will give birth early," researcher Panagiotis Tsiartas, said.
"We will need to conduct further studies before the method can be used in full, but if the results of these studies are good, the test will hopefully lead to new types of treatments to prevent premature birth and treat the serious complications resulting from it," Tsiartas said in a statement.
The study was published in the British Journal of Obstetrics and Gynaecology.