Predictive value of sFlt-1, PlGF, sFlt-1/PlGF ratio and PAPP-A for late-onset preeclampsia and IUGR between 32 and 37 weeks of pregnancy

Objectives: The aim of this study was to investigate, whether maternal serum levels of sFlt-1, PlGF and PAPP-A at third trimester of pregnancy are associated with late-onset PE and intrauterine growth retardation (IUGR) after 34 weeks of pregnancy. Methods: This was a prospective study measuring the maternal serum levels of soluble tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A) at 32-37 weeks of pregnancy: 730 patients were enrolled and 676 had neither intrauterine growth restriction (IUGR) nor preeclampsia (PE) or pregnancy induced hypertension (PIH) throughout the pregnancy. 22 patients developed IUGR, 32 PE and 24 PIH. Results: Linear regression analyses after adjusting for maternal age, gestational age at the blood sampling and maternal BMI showed associations between PE and serum sFlt-1 levels (Exp(beta) = 3.29; 95% CI: 2.69-4.04), serum PlGF levels (Exp(beta) = 0.18; 95% CI: 0.13-0.24), sFlt-1/PlGF ratio (Exp(beta) = 15.59; 95% CI: 10.64-22.84) and serum PAPP-A (Exp(beta) = 1.48; 95% CI 1.15-1.89). sFlt-1, PlGF and sFlt-1/PlGF-Ratio showed comparable area under the curve (AUC) estimates with a predictive ability to discriminate pregnancies developing PE and IUGR from controls. The predictive ability of PAPP-A for PE was only slightly better than chance. Conclusions: This study supported the ability of a single measurement of sFlt-1/PlGF ratio at third trimester to predict PE and IUGR occurring after 34 weeks of pregnancy. However, larger multicentre studies are needed to replicate our results.