Comparison of three commercially available placental growth factor-based tests in women with suspected preterm pre-eclampsia: the COMPARE study

Ultrasound Obstet Gynecol. 2019 Jan;53(1):62-67. doi: 10.1002/uog.19051. Epub 2018 Dec 5.


Objective: To compare the performance of three placental growth factor (PlGF)-based tests in predicting delivery within 14 days from testing in women with suspected preterm pre-eclampsia before 35 weeks' gestation.

Methods: This was a retrospective analysis of samples collected from three prospective pregnancy cohort studies. Participants were pregnant women with suspected preterm pre-eclampsia recruited in tertiary maternity units in the UK and Ireland. Samples were analyzed simultaneously according to the manufacturers' directions. The tests compared were the DELFIA Xpress PlGF 1-2-3 test, the Triage PlGF test and the Elecsys immunoassay soluble fms-like tyrosine kinase-1 (sFlt-1)/PlGF ratio. Areas under receiver-operating characteristics curves (AUCs) were compared. The main outcome measure was detection of a difference of 0.05 in AUC between tests for delivery within 14 days of testing.

Results: Plasma samples from 396 women and serum samples from 244 women were assayed. In predicting delivery within 14 days secondary to suspected pre-eclampsia prior to 35 weeks' gestation, no significant differences were observed in AUCs (P = 0.795), sensitivities (P = 0.249), positive predictive values (P = 0.765) or negative predictive values (P = 0.920) between the three tests. The specificity of the Elecsys sFlt-1/PlGF ratio test was higher than that of the other two tests (P < 0.001).

Conclusions: The tests perform similarly in their prediction of need for delivery within 14 days in women with suspected pre-eclampsia. The high negative predictive values support the role of PlGF-based tests as 'rule-out' tests for pre-eclampsia. © 2018 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Keywords: DELFIA Xpress PlGF 1-2-3 test (Perkin Elmer); Elecsys immunoassay sFlt-1/PlGF ratio (Roche); Triage PlGF (Alere); placental growth factor; pre-eclampsia; soluble Flt-1.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Biomarkers / blood*
  • Cohort Studies
  • Female
  • Gestational Age
  • Humans
  • Placenta Growth Factor / blood*
  • Pre-Eclampsia / blood
  • Pre-Eclampsia / diagnosis*
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Trimester, Third
  • Prenatal Diagnosis*
  • Prospective Studies
  • Retrospective Studies


  • Biomarkers
  • Placenta Growth Factor