A revolutionary device that tells anxious mothers-to-be exactly when they are about to give birth could be on sale within the year.

The labour prediction kit promises to end the agonising uncertainty experienced by expectant women in the final weeks of pregnancy.

Its backers claim the labour predictor will one day be as commonplace as the home pregnancy test. It will be available over the counter in chemists for between £20 and £70.

Currently, due dates given by hospitals are only approximate. Contractions can come as much as two weeks early or late. The new device, currently in prototype form, should pinpoint delivery to within 48 hours.

"The end of pregnancy is a period of incredible uncertainty. This device is about preparing women and making them feel a little more secure," said Deborah Withington, professor of auditory neuroscience at Leeds University and a director of Jopejo Ltd, the company that is developing the new device.

The device picks up faint electrical signals in the womb via electrodes placed on the woman's abdomen. Prior to labour, those electrical signals can be interpreted to give mothers-to-be advance warning of when contractions will begin.

The new device will have three lights on it. Pregnant women who get the green light can confidently expect labour to start within 48 hours. An amber light means contractions will take place within two weeks. The red light indicates contractions will not begin for at least two weeks.

The labour predictor can differentiate between real contractions and Braxton Hicks – or false – contractions. The device would also give mothers the chance to make sure existing children are looked after when labour begins and would also warn partners whether they need to stay close to home or be able to go on, for example, business trips without worry.

Professor Withington said: "Some people have turned around and said: 'We don't want to know the real due date because it takes the surprise out.' But people said that about pregnancy kits when they first came out, and who says that now?"

The project, which is the brainchild of two eminent obstetricians in Leeds – Nigel Simpson, a consultant obstetrician at Leeds General Infirmary and Professor James Walker, of the city's St James University Hospital – received a £750,000 cash injection last week. With this backing the device could be in mass production by the end of the year.

Mr Simpson said the kit would also allow mothers to measure a baby's heartbeat in the womb, providing reassurance to mums who have not felt their baby kicking but do not want to go immediately to hospital for tests.

"We are currently at the development stage," he added, "At the moment it's a hospital-based device. The task is to find a suitable design and specification for the home use market."