Second-trimester maternal serum placental growth factor and vascular endothelial growth factor for predicting severe, early-onset preeclampsia

OBJECTIVE: To determine whether alterations in second-trimester maternal serum cytokine concentrations can identify women at risk for developing severe, early-onset preeclampsia. METHODS: Patients with severe preeclampsia requiring delivery prior to 34 weeks (n = 20) were each matched by gestational age, gravidity, parity, and sample freezing time with three healthy controls who delivered at term (n = 60). By using second-trimester maternal sera originally collected for fetal aneuploidy screening, the concentrations of placental growth factor, vascular endothelial growth factor, granulocyte colony-stimulating factor, endothelin-1, and human chorionic gonadotropin were compared between patients and controls. Logistic regression analysis was used to estimate odds ratios for high versus low (median split) cytokine concentrations with respect to the development of severe, early-onset preeclampsia. Receiver operating characteristic (ROC) curves based on a second logistic regression, using actual cytokine values, were plotted to illustrate reciprocal impact on sensitivity and specificity. RESULTS: Placental growth factor and vascular endothelial growth factor levels were significantly lower in patients than in controls. No significant differences were observed for the other cytokines. The odds ratios (with 95% confidence intervals) were 15.54 (3.29, 73.40) for vascular endothelial growth factor and 4.20 (1.35, 13.06) for placental growth factor. Receiver operating characteristic analysis of placental growth factor and vascular endothelial growth factor confirmed that both were useful in discriminating between patients and controls. Models combining both vascular endothelial growth factor and placental growth factor provided the best performance for identifying patients at risk for developing severe, early-onset preeclampsia, according to both odds ratios and ROC analyses. CONCLUSION: Combined analysis of placental growth factor and vascular endothelial growth factor is potentially useful as a tool for early identification of patients at risk for developing severe, early-onset preeclampsia.