Accuracy of circulating placental growth factor, vascular endothelial growth factor, soluble fms‐like tyrosine kinase 1 and soluble endoglin in the prediction of pre‐eclampsia: a systematic review and meta‐analysis

Abstract

Biomarkers have been proposed for identification of women at increased risk of developing pre-eclampsia. To investigate the capacity of circulating placental growth factor (PlGF), vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin (sENG) to predict pre-eclampsia. Medline and Embase through October 2010 and reference lists of reviews, without constraints. We included original publications on testing of PlGF, VEGF, sFLT1 and sENG in serum or plasma of pregnant women at <30 weeks of gestation and before clinical onset of pre-eclampsia. Two reviewers independently identified eligible studies, extracted descriptive and test accuracy data and assessed methodological quality. Summary estimates of discriminatory performance were obtained. We included 34 studies. Concentrations of PlGF (27 studies) and VEGF (three studies) were lower in women who developed pre-eclampsia: standardised mean differences (SMD) -0.56 (95% CI -0.77 to -0.35) and -1.25 (95% CI -2.73 to 0.23). Concentrations of sFLT1 (19 studies) and sENG (ten studies) were higher: SMD 0.48 (95% CI 0.21-0.75) and SMD 0.54 (95% CI 0.24-0.84). The summary diagnostic odds ratios were: PlGF 9.0 (95% CI 5.6-14.5), sFLT1 6.6 (95% CI 3.1-13.7), sENG 4.2 (95% CI 2.4-7.2), which correspond to sensitivities of 32%, 26% and 18%, respectively, for a 5% false-positive rate. PlGF, sFLT1 and sENG showed modest but significantly different concentrations before 30 weeks of gestation in women who developed pre-eclampsia. Test accuracies of all four markers, however, are too poor for accurate prediction of pre-eclampsia in clinical practice.