A new study by researchers from Guy’s and St Thomas’ and King’s College London has found that a simple blood test can help accurately and rapidly diagnose a common and potentially fatal pregnancy complication.

The research, published in the Lancet, showed that measuring placental growth factor (PLGF) helped doctors to diagnose women with pre-eclampsia on average two days sooner. They also showed that this improved outcomes for women significantly.

The team of scientists from found that by measuring the concentration of placental growth factor (PLGF) in a woman’s blood, doctors were able to diagnose pre-eclampsia on average two days sooner.

Pre-eclampsia is a condition that affects some pregnant women, usually during the second half of pregnancy or soon after their baby is delivered. It affects up to 6% of pregnancies and is suspected in aroud 10%. Although most cases of pre-eclampsia cause no problems and improve soon after the baby is delivered, there’s a risk of serious complications that can affect both the mother and her baby. Globally, 100 women die as a result of the condition every day.

The research showed that the test and associated improvement in diagnosis times led to a significant improvements in outcomes for women.

Lead author Professor Lucy Chappell, NIHR Research Professor in Obstetrics at King’s said: “For the last hundred years, we have diagnosed pre-eclampsia through measuring blood pressure and checking for protein in a woman’s urine. These are relatively imprecise and often quite subjective.

“We knew that monitoring PLGF was an accurate way to help detect the condition but were unsure whether making this tool available to clinicians would lead to better care for women. Now we know that it does.”

The research involved 1,035 women with suspected pre-eclampsia, who were recruited to the study from 11 maternity units across the UK. Women were randomly assigned to two groups. One had their PLGF test results made available to their clinical team, the other did not.

PLGF testing was shown to reduce the average time to pre-eclampsia diagnosis from 4·1 days to 1·9 days and serious complications before birth (such as eclampsia, stroke, and maternal death) from 5% to 4%.

There was no change in the likelihood of complications for the baby, the age at which babies were delivered prematurely or whether they were admitted to a neonatal unit. It was important that this test did not cause more unnecessary cases of preterm birth for babies.

In response to the trial, NHS England has announced that they would be making the test more widely available across the NHS.

Professor Tony Young, national clinical lead for innovation at NHS England, said: “This innovative blood test, as set out in this new study, helps determine the risks of pre-eclampsia in pregnancy, enabling women to be directed to appropriate care or reduce unnecessary worry more quickly.

“The NHS, with partners in government, will be making this test more widely available across the NHS as part of our plans to ensure as many patients as possible can benefit from world-class health innovations.”

Professor Chappell added: “The evidence shows that widespread PLGF testing could saves lives and it is fantastic news that NHS England agree. Many tests have come into practice without robust assessment. This time, we have evaluated this new test and shown that it improves care and outcomes for pregnant women and their babies.”

Sue Ziebland, Professor of Medical Sociology at the University of Oxford and programme director at the NIHR, said: “We funded this research to provide a conclusive answer as to whether PLGF testing does help clinicians to detect pre-eclampsia, a pragmatic research question typical of those funded by the NIHR.

“We’ll be working with other national healthcare organisations to ensure the results of this study are taken up as soon as possible, so that thousands of women can get care more quickly and prevent the dangerous effects of this condition.”

The research was supported by NIHR Research for Patient Benefit, and by the NIHR Research Professorship awarded to Professor Lucy Chappell.