The blood test, conducted by Oxford University Hospitals (OUH) NHS Foundation Trust at its John Radcliffe Hospital, measures the ratio of two placental factors - maternal serum soluble fms-like tyrosine kinase (sFlt-1) and placental growth factor (PlGF) - that are released into the mother’s blood.
The test was developed by Roche Diagnostics, who have funded a trial conducted at the Women’s Centre at the John Radcliffe Hospital.
The trial results were successful and the response from maternity staff so enthusiastic that the test has been accepted as routine clinical practice at OUH. The introduction of the test will be cost-neutral for the trust.
Pre-eclampsia is a serious disease that occurs in four per cent of all pregnancies. It causes high blood pressure, protein in the urine and oedema and can result in liver failure, kidney failure and seizures in the mother. It can lead to restricted growth in the baby and often premature delivery.
Without the test, there is no accurate method to determine who will get the disease. Currently, any patients with suspected PE are often admitted to hospital, sometimes for several days in order to make the diagnosis. PE is diagnosed by excluding all the other possible causes of high blood pressure and protein in the urine through a series of tests, which take time and cause anxiety for the mother-to-be and her family.
The trial (currently awaiting publication) was led by Dr Manu Vatish, OUH Consultant Obstetrician and Senior Clinical Fellow with the University of Oxford’s Nuffield Department of Women’s and Reproductive Health.
He said: “The stress experienced by mums and their families can be put into context when we see that almost 70 per cent of patients admitted don't actually have PE.
“With this study and the previously published work, we have shown that we can virtually eliminate all those patients who have no risk of developing pre-eclampsia, allowing us to focus our attention on those with an increased risk.”
Dr Vatish added: “The standard clinical tests for pre-eclampsia, which work on the assumption that all patients are at risk, are fairly good at predicting which women could go on to develop the disease. Using the new test together with standard clinical practice, this figure rises to 100 per cent.
“This approach – using the test in conjunction with standard clinical practice – allows us effectively to segregate patients into those who have virtually no risk of getting the disease and those with an increased risk. This test improves our diagnostic accuracy and is a welcome step forwards.”
Tim James, OUH Head Biomedical Scientist in Clinical Biochemistry, whose laboratories carried out the tests, said: “The beauty of these tests is that they are not reliant on analysers that are only available in Oxford. The instruments are available at many hospital sites, meaning that the benefits we have demonstrated can be expanded across the UK relatively rapidly and easily, and pregnant women everywhere should be able to benefit".