Longitudinal evaluation of predictive value for preeclampsia of circulating angiogenic factors through pregnancy

OBJECTIVE: The purpose of this study was to examine whether longitudinally sampled maternal angiogenic concentrations predict preeclampsia. STUDY DESIGN: Plasma sFlt-1 and placental growth factor (PlGF) concentrations in healthy pregnant women were quantified at 10, 17, 25, and 35 weeks' gestation. Preeclampsia was diagnosed with criteria from the American College of Obstetricians and Gynecologists. RESULTS: In the first trimester, sensitivity/specificity for PlGF and sFlt-1 were 55/43% and 57/40%, respectively, and did not improve appreciably as the pregnancy progressed. Among pregnancies that later experienced preeclampsia, median PlGF was lower beginning in the second trimester, but sFlt-1 was not higher until the third trimester. Analyte positive predictive values approached 10% in the third trimester. Negative predictive values were >90% for the entire pregnancy. CONCLUSION: Prediction of preeclampsia in early pregnancy was not possible with the use of maternal angiogenic protein concentrations. Even in late pregnancy, positive predictive values were not useful clinically. Negative predictive values are similarly unlikely to prove useful as a tool with which to a rule out suspected disease.