Simple spit test designed to detect pre-eclampsia in the early stages

May 4 2007

A simple spit test designed to detect pre-eclampsia in the early stages is being trialed in a UK hospital, reports Cath O'Driscoll in Chemistry & Industry, the magazine of the SCI.

The test, which is designed to be used at home, will allow mums-to-be to check for themselves whether they are at risk of the condition, which can be symptomless in the early stages but kills 1000 babies in the UK every year. The test is expected to be more reliable than the traditional blood pressure and urine tests conducted in GPs' offices and hospitals.

Pre-eclampsia is also a leading cause of maternal mortality, killing one woman globally every six seconds, according to the UK's Action on Pre-eclampsia (APEC). Earlier detection and intervention could save lives.

Standard blood pressure and urine tests are unreliable, and there is a lot of scope for "user error", according to Michael Rich, chief executive of APEC. In addition, high blood pressure can be caused by a variety of factors other than pre-eclampsia, and even when a woman develops pre-eclampsia, problems with high blood pressure may not occur until the latter stages.

The new test works by monitoring levels of urate, a salt of uric acid, increased levels of which are thought to be due to impaired kidney excretion in pre-eclampsia.

'A salivary urate test is simple, non-invasive, quick and cheap and can be done at any time. As a metabolic test independent of blood pressure, it may obviate the need for hospital admission,' said retired hospital rheumatologist Brian Owen-Smith, who invented the test.

The trial, which will eventually involve 1000 women, is underway at St Richards Hospital in Chichester. Trial subjects send away saliva-wiped swabs for analysis. Results are expected early next year. The ultimate aim is to develop a "traffic light" detection kit for use in the home.

Pre-eclampsia is thought to be the result of problems relating to the implantation of the placenta. The main diagnostic symptoms are raised blood pressure and the excretion of protein in the urine. While there is no cure, other than the delivery of the baby and removal of the faulty placenta, early detection and management of the problem can have a big impact on patient outcome.