138. Placental growth factor to assess and diagnose hypertensive pregnant women: A stepped wedge randomised controlled trial (PARROT)

Abstract

Introduction Angiogenic factor measurements have shown potential for assisting in the diagnosis of pre-eclampsia in prospective cohort studies, but their diagnostic ability and clinical impact when revealed to clinicians remains uncertain. Hypothesis In women presenting with suspected pre-eclampsia, use of placental growth factor (PlGF) testing decreases time to clinician-recognised diagnosis of pre-eclampsia (primary outcome) and decreases maternal and perinatal morbidity, and has an impact on health resource use (secondary outcomes). Methods Design: Multi-centre, pragmatic, stepped-wedge cluster randomised controlled trial. Setting: Eleven UK maternity units (size range 3000–9000 deliveries per annum). Intervention: PlGF measurement with result revealed to clinical team and management guidance. Randomisation: Hospitals were randomly allocated to the order in which the intervention was implemented. Population: Women who presented to maternity services with suspected pre-eclampsia between 20 + 0 and 36 + 6 weeks’ gestation, providing individual-level consent. Results Between June 2016 and October 2017, 1023 women with suspected pre-eclampsia were recruited. The median time to diagnosis of pre-eclampsia was from 4.1 days (usual care) to 1.9 days with PlGF testing (time ratios 0.39 (95% CI 0.17–0.91) by parametric survival analysis). There was a reduction in maternal severe adverse outcomes (as defined in the fullPIERS consensus) from 5.4% (concealed PlGF group) to 3.8% (revealed PlGF group) adjusted OR 0.32 (95% CI 0.11–0.96) with no evidence of a significant difference in perinatal adverse outcomes. Discussion PlGF testing has been shown to be acceptable and clinically useful in substantially reducing the time to clinical recognition of pre-eclampsia. Where PlGF is implemented there is a reduction in maternal adverse outcomes, consistent with targeted enhanced surveillance as recommended in the trial management guidance for clinicians. Adoption of PlGF testing in women with suspected pre-eclampsia is supported by the results of this study.