Scientists are developing a blood test for ectopic pregnancies, which could help save the fertility of thousands of women.
It would enable the life-threatening condition to be diagnosed within a day, instead of the several weeks it takes for tests to come back now.
This would allow doctors to intervene earlier to save reproductive organs which are often severely damaged by the condition.
Ectopic pregnancies occur when the foetus implants itself outside of the womb, usually in one of the fallopian tubes. The baby can never be saved, but if the condition is not diagnosed in time it can also be fatal for the mother – there are about five such deaths in Britain every year.
Doctors currently use blood screening and ultrasound to detect abnormalities, but these methods are not accurate in the early stages following conception.
However, the blood test could be accurate just three weeks into pregnancy.
It would enable women to have immediate surgery to remove the foetus, reducing the chances of the fallopian tube being damaged.
The test, which has been developed by doctors at the University of Pennsylvania School of Medicine in the U.S., checks for four characteristics or `markers` in the blood which are symptomatic of an ectopic pregnancy.
"Potentially this could be a test that somebody in early pregnancy could use to diagnose ectopic pregnancy," the Daily Mail quoted Dr Mary Rausch addressing the American Society for Reproductive Medicine conference in Denver, Colorado, as saying.
"If they are definitely diagnosed with an ectopic pregnancy, then they could be immediately treated," she added.
The researchers took blood samples from 100 women who had already had an ectopic pregnancy and compared them with samples from 100 healthy women.
They found they were correctly able to diagnose 42 per cent of ectopic pregnancies.