Placental growth factor testing may expedite pre-eclampsia diagnosis

By Nicole MacKee
Placental growth factor (PlGF) testing in women with suspected pre-eclampsia after 20 weeks’ gestation can help to expedite a confirmed diagnosis, researchers say.

A cluster-randomised controlled trial in 11 maternity units in the UK, published inThe Lancet, evaluated the role of PlGF testing in 1023 women with suspected pre-eclampsia between 20 weeks’ and 36 weeks and 6 days’ gestation. In the trial, 576 women were assigned to PlGF testing along side a clinical management algorithm, and 447 women were assigned to the control group. This control group also had PlGF testing, but the results were concealed from both the women and their clinicians, and they were offered usual care.

The researchers found that the median time to diagnosis was 1.9 days in the intervention group and 4.1 days in the concealed testing group. Maternal severe outcomes were reported in 22 women (4%) in the intervention group and 24 women (5%) in the concealed testing group. No difference was found between the groups in perinatal adverse outcomes and gestational age at delivery.

The researchers said the ability to diagnose pre-eclampsia more rapidly enabled targeted, individualised management.

Professor Angela Makris, Obstetric and Renal Physician and President of the Society of Obstetric Medicine of Australia and New Zealand, said the findings of this well-designed trial were important.

‘Use of the test did reduce the incidence of maternal adverse outcomes that would be considered clinically very important, most likely due to better identification of women who have pre-eclampsia. The rapidity of adverse outcomes can be hard to predict in women,’ Dr Makris said. ‘[The PlGF test] also has the benefit of being a point-of-care test and, as such, makes it easier to access for remote medical facilities.’

She added that PlGF testing could be useful in some rural settings where it was difficult for women to return to a clinic for follow-up testing to confirm a pre-eclampsia diagnosis.

PlGF testing is not routinely used in Australia, but a test assessing the ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to PlGF is used by some Australian hospitals to diagnose pre-eclampsia or predict if it will develop in the near future. The ratio test was shown to be effective by Australian and international researchers in the Prediction of Short-Term Outcome in Pregnant Women with Suspected Pre-eclampsia Study (PROGNOSIS; N Engl J Med 2016; 374: 13-22).

Dr Makris said the UK findings strengthened the case for wider use of PlGF testing in diagnosis, but more research was needed. She said the findings of two ongoing multicentre trials would determine if the UK results were replicable.
Lancet 2019;