Inhibin-A Augments Plgf and the Sflt-1 / Plgf Ratio in the Prediction of Preeclampsia and / or Fgr near Delivery

Objective: We previously provided evidence to confirm that soluble Fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and their ratio, are useful tools to direct the management of preeclampsia (PE), fetal growth restriction (FGR), and PE+FGR near delivery. In this study we examine the potential additive value of Inhibin-A, a hormone marker of the transforming growth factor family. Methods: We used a cohort of 125 pregnant women enrolled near delivery at clinics of the University Medical Center of Ljubljana, Slovenia. There were 31 cases of PE, 16 of FGR, 42 of PE+FGR, 15 iatrogenic preterm delivery (PTD), and 21 unaffected controls with delivery of a healthy baby at term. Cases delivered before 34 weeks’ gestation included 13 of PE, 12 of FGR, 22 of PE+FGR, and 6 of PTD. We recorded demographic characteristics and medical history and the levels of PlGF, sFlt-1 and Inhibin-A. The predictive accuracy of each biomarker, their ratios, and combinations was estimated from areas under the curve (AUC) of Receiver Operating Characteristics (ROC) curves. We estimated accuracy by the continuous marker model and a cut-off model. Results: Combining Inhibin-A with PlGF or with the sFlt-1 / PlGF ratio showed a 10-20% increase in AUCs and 5-15% increase in the detection rate, at 10% false positive rate, of PE, and a lower, but significant, increase for PE+FGR but not for FGR alone. The use of a cut-off model was adequate, although a bit higher accuracy was obtained from the continuous model. Highest correlation was found for PlGF with all three complications. Conclusion: Inhibin-A improves the accuracy of predicting PE and PE+FGR provided by the angiogenic markers alone, bringing the results to a diagnostic level, thus assisting in directing clinical management. Inhibin-A had no added value for the accuracy of predicting FGR alone.