A simple blood test could help save many women from investigations and interventions for pre-eclampsia
A simple new blood test could help save many women from unnecessary investigations and interventions for pre-eclampsia, the annual conference of the College of Pathologists heard in Sydney.
Professor Shaun Brennecke, director of the department of maternal-fetal medicine at the Royal Women’s Hospital, together with international collaborators, published a study on the predictive value of the test last year, and he has been determining its clinical utility and cost-effectiveness in an Australian setting since.
The test was excellent at excluding pre-eclampsia, the study found.
“Specifically, you had 95% chance of not developing pre-eclampsia in the next month if there was a low reading,” he said. “And if you had a high result, then you had a 40% chance of developing pre-eclampsia in the next month.”
The test works by measuring the ratio of certain proteins identified by researchers a decade ago as being associated with pre-eclampsia.
Increased levels of soluble fms-like tyrosine kinase 1 (sFlt-1) and decreased placental growth factor (PlGF) levels in the mother, or a high sFlt-1:PlGF ratio, was an indicator of an increased likelihood of pre-eclampsia.
Pre-eclampsia accounted for around 5% of pregnancies, but a test like this would be best used in women with signs indicating a risk of the disease, and in the latter half of the pregnancy, Professor Brennecke said.
At the moment, women with suspected pre-eclampsia are admitted to maternal wards or pregnancy day care centres for monitoring. But this can be expensive, time-consuming and disruptive for many families, especially those in rural and regional Australia.
“If you take a group of women who have symptoms or signs suggestive of the possibility they may be developing pre-eclampsia, only 20% of those women will go on to develop the disease,” he said.
This test would be a way of excluding women who would not become pre-eclamptic, even if they showed some clinical indication that they might develop it, he said.
“That’s very helpful because the 80% who won’t can be safely sent home and be treated with normal antenatal care, whereas the 20% who have a positive test need much higher surveillance and there is time to effectively intervene to optimise the health outcomes for the mother and the baby.”
As well as saving women the unnecessary transfer to metropolitan areas, better discrimination of women would help to allocate resources to those that need them the most, he said.
There are also “obvious cost savings” from performing a blood test likely to cost under $100, compared with the thousands of dollars a day that it costs to monitor a woman in a maternity ward, he said.
The test still needs to be assessed for cost-effectiveness in an Australian setting, so a national rollout is still a long way off.
The group was optimistic it would have a role in the future though, Professor Brennecke said.