OBJECTIVE
To determine if maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30–34 weeks can identify mothers at risk for preeclampsia (PE), stillbirth and small-for-gestational-age neonates (SGA).
STUDY DESIGN
A prospective cohort study included 1269 singleton pregnant women who had blood samples obtained at 30–34 weeks and delivered after 34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by ELISA.
RESULTS
The prevalence of late (>34 weeks) PE, severe late PE, stillbirth and SGA was 3.2% (n=40), 1.8% (n=23), 0.4% (n=5) and 8.5% (n=108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late PE [adjusted odds ratio (aOR) 16]; addition of PlGF/sEng to clinical risk factors increased the area under the ROC curve (AUC) from 0.76 to 0.88 (p=0.03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20–25 weeks for the prediction of severe late PE (comparison of AUC; each p≤0.02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false positive rate of 15% for the identification of severe late PE. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30–34 weeks had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80% and specificity 93%) were observed in a separate case-control study. Integrating these biomarkers with clinical data did not improve the prediction of SGA.
CONCLUSIONS
Risk assessment for severe late PE and stillbirth in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and anti-angiogenic factors at 30–34 weeks of gestation.