The prediction of preeclampsia: Reassessment of clinical value of increased plasma levels of fibronectin

Objective: To determine whether assessment of plasma fibronectin in primigravidae could predict the pregnant women expected to become preeclamptic. Methods: We performed a prospective blinded analysis of 156 apparently normotensive primigravidae in an outpatient clinic. Blood samples were taken at 6 week intervals from the 18th week and immediately after delivery or at the onset of preeclampsia. Plasma fibronectin was evaluated by ELISA. Evolution with gestational age was studied using regression curves. Results: We had 148 normal primigravidae (592 determinations). In three women, increased fibronectin anticipated preeclampsia by 3–4 weeks. Five women showed high levels only at the onset of preeclampsia. Sensitivity, specificity, positive and negative predictive values of increased fibronectin levels were 37.5% (95% CI=3.3–71.7), 96.6% (95% CI=93.7–99.6), 37.5% (95% CI=3.3–71.7) and 96.6% (95% CI=93.7–99.6), respectively. Conclusions: This study shows that plasma fibronectin levels could represent a specific marker for preeclampsia. Its sensitivity has to be improved but its high negative predictive value strongly argues against the development of preeclampsia within the next 4 weeks after the blood sampling.