Placental growth factor measurements in the assessment of women with suspected Preeclampsia: A stratified analysis of the PARROT trial.

Kate E Duhig,Lucy C Chappell,Joanna C Girling,Derek Tuffnell,Andrew H Shennan,Jenny E Myers,Nigel A.B Simpson,Kate Harding,Chris Gale,Andrew Sharp,Paul T Seed

doi:10.1016/j.preghy.2020.10.005

Abstract

Placental growth factor testing decreases time to recognition of preeclampsia and may reduce severe maternal adverse outcomes. This analysis aims to describe the clinical phenotype of women by PlGF concentration, and to determine the mechanism(s) underpinning the reduction in severe maternal adverse outcomes in the PARROT trial, in order to inform how PlGF testing may be optimally used within clinical management algorithms. This was a planned secondary analysis from the PARROT trial that compared revealed PlGF testing and management guidance with usual care in the assessment of women with suspected preterm preeclampsia. Maternal and perinatal outcomes following stratification of women by trial group, and measured PlGF concentration. 1006 women were included. PlGF<100pg/ml identified women with more marked hypertension, increased adverse maternal outcomes and preterm delivery rates, and higher rates of small for gestational age infants. There was a reduction in adverse maternal outcomes in women whose results were revealed when PlGF levels were 12-100pg/ml compared to usual care (3.8% vs 6.9%; aOR 0.15(95% CI 0.03-0.92). There was no significant difference in gestation at delivery between concealed or revealed groups in any PlGF categories. Low PlGF concentrations are associated with severe preeclampsia. The reduction in severe adverse maternal outcomes may be mediated through quicker diagnosis and intensive surveillance, as recommended by the management algorithm for those at increased risk. PlGF is particularly beneficial in those who test 12-100pg/ml, as these may be women with silent multi-organ disease who otherwise may go undetected.

Highlights

Preeclampsia complicates around 3% of singleton pregnancies, with hypertension affecting 10% of pregnant women [1,2,3]
Women in the control group received usual care following local hospital practice based on 2010 National Institute of Health and Care Excellence (NICE) guidance on the management of hypertension in pregnancy [13], with an additional blood sample taken for concealed Placental Growth Factor (PlGF) testing
We have previously reported that a fixed PlGF threshold of

Summary

Introduction

Preeclampsia complicates around 3% of singleton pregnancies, with hypertension affecting 10% of pregnant women [1,2,3]. Evidence from prospective cohort studies has shown that angiogenic factors have good test performance for identifying preterm preeclampsia [10,11] These studies included women in whom angiogenic factor concentrations were concealed to carers. A recent randomised trial (PARROT) of 1023 women evaluated revealed PlGF measurement with a clinical management algorithm against usual care, forming one of the largest studies of angiogenic factors in the management of suspected preterm preeclampsia. In this trial there was a clinically important reduction in time to diagnosis of preeclampsia with a concurrent reduction seen in severe maternal adverse outcomes with revealed PlGF testing [12]

Methods

Results

Conclusion