Comparison of activin A and cell-free fetal DNA levels in maternal plasma from patients at high risk for preeclampsia

OBJECTIVES: We examined the concentration of activin A in a prospective manner before the clinical manifestation of preeclampsia and compared the data with those of cell-free fetal DNA in the maternal plasma. METHODS: The levels of activin A were analysed by enzyme-linked immunosorbent assay (ELISA) for pregnant women: (1) with preeclampsia (n = 34) in the third-trimester and normal controls (n = 44); and (2) at-risk of preeclampsia in the second-trimester (n = 15) as indicated by uterine artery Doppler and normal controls (n = 68). Correlation between activin A level and cell-free fetal DNA level was examined using the Spearman rank test. RESULTS: The level of plasma activin A was significantly higher in the preeclamptic samples (12.056 vs 7.068 ng/mL, p = 0.000). The increase in the activin A concentration was observed prior to the onset of preeclampsia (3.483 vs 1.324 ng/mL, p = 0.000). This increase in activin A correlated significantly with the increased level of cell-free fetal DNA, in the maternal circulation prior to the onset of preeclampsia (r = 0.977, p = 0.000). CONCLUSION: Our data suggest that circulatory activin A could be an independent biomarker for the early identification and monitoring of preeclampsia.