The home test that could save 1,000 babies a year

The kit, which monitors a woman's saliva for telltale signs of the dangerous condition, could be available in as little as three years.

The brainchild of retired consultant Brian Owen-Smith, it could save the lives of mothers and babies by predicting the condition more accurately and earlier than current tests.

One of the most common causes of premature birth in the UK, pre-eclampsia claims the lives of up to 1,000 babies and ten mothers a year.

Affecting around 70,000 British women a year, and characterised by high blood pressure, it can cause convulsions, blood clots, liver damage and kidney failure.

TV presenter Melinda Messenger and singer Sophie Ellis-Bextor had to have emergency Caesarean operations after doctors diagnosed pre-eclampsia.

Although they both gave birth to healthy sons, many families are not as fortunate.

Current tests for diagnosis - usually carried out by midwives during antenatal classes - involve blood pressure checks and urine samples.

However, they are far from infallible.

The new test looks for the presence of urate in the mother's saliva.

Produced naturally by the breakdown of food, levels of urate have been shown to increase during pre-eclampsia, which is caused by a problem with the placenta.

A mother-to-be takes a saliva sample by briefly placing a small pad under her tongue.

She then squeezes the liquid onto a special strip which is fed into a digital meter capable of measuring urate levels.

The meter could be calibrated to operate on a "traffic light" system, with a green result signifying all is well, yellow a potential problem and red the need to seek immediate medical help.

Testing is likely to be carried out weekly, from half-way through pregnancy.

Already being trialled at St Richard's Hospital in Chichester, the Salurate test could be on the market by the end of the decade.

Costing less than £100 a kit, it will only become available on the NHS if the Government's medical treatment rationing body, the National Institute for Health and Clinical Excellence, decides its benefits outweigh its cost.

It is hoped women will be able to use it in the comfort of their own home, where they will take a saliva sample by briefly placing a small pad under the tongue.

The saliva is then squeezed out onto a strip of paper and fed into a digital meter which will measure urate levels.

Carried out weekly, it will give women early warning of the onset of pre-eclampsia, the magazine Chemistry & Industry reports

Those at risk could be given blood pressure drugs and other treatments designed to delay the progress of the condition.

As the only cure is early delivery of the baby, the extra notice would also allow doctors to plan the Caesarean, rather than carrying out an emergency operation.

Dr Owen-Smith said: "All one really wants to do is devise a test that would be of benefit to mothers, unborn babies and midwives.

"A salivary urate test is simple, non-invasive, quick and cheap."

Michael Rich, of charity Action on Pre-Eclampsia, said the test could be of particular use to women at high risk of the condition, including older mothers, the obese and those who suffered it in an earlier pregnancy.

He added that while several different tests are being developed around the world, this one appears particularly easy to use.

"It is a simple test. It is non-invasive, so women won't mind doing it and if it works, it will probably end up saving lives."

Researchers in Canada are developing a blood test for the condition and believe carbon monoxide - the poisonous gas found in cigarette smoke, could hold the key to preventing it from occurring.

Researchers in Toronto are focussing on a protein produced by the mother-to-be's immune system.

Released by the placenta, the compound disguises the baby's genetic material, ensuring the developing child is not rejected by the mother's body.

Studies have shown that women who develop pre-eclampsia have lower that average levels of the protein, suggesting it could form the basis of a blood test for the condition.

Work in Ontario shows that carbon monoxide, found in cigarette smoke and exhaust fumes, protects against pre-eclampsia.

Professor Andrew Shennan (CORR), an obstetrician and advisor to baby charity Tommy's, said:

"Pre-eclampsia is a serious illness which can have grave consequences for both mother and baby if left undetected, therefore any progress which can be made into identifying at risk women is crucial.

"Increased levels of urate are a good indicator in identifying women suffering from pre-eclampsia, however its predictive powers are not definitive.

"Whilst this new test could potentially prove useful owing to its simplicity of use, it is important that more research is done into understanding and preventing other contributing factors."