The addition of activin A and inhibin A measurement to uterine artery Doppler velocimetry to improve the early prediction of pre-eclampsia

OBJECTIVE: To evaluate whether the measurement of maternal serum activin A and inhibin A adds any clinically relevant information for the prediction of pre-eclampsia in women with altered uterine artery Doppler velocimetry at 24 weeks of gestation. METHODS: This was a prospective, controlled, hospital-based study involving 58 asymptomatic pregnant women at 24 weeks' gestation in whom a diastolic notch of the uterine artery waveform was noted at routine Doppler examination. Doppler assessment of the uterine artery waveform and measurement of maternal activin A and inhibin A serum levels by specific two-site enzyme immunoassays were performed. The cut-off points for defining 'high' serum activin A and inhibin A levels for prediction of pre-eclampsia were chosen by receiver-operating characteristics (ROC) curve analysis. The probability of developing pre-eclampsia was calculated for several combinations of results of hormone testing. RESULTS: Activin A and inhibin A levels were higher in patients who developed pre-eclampsia (n = 18; mean +/- standard error: 2.69 +/- 0.35 ng/mL and 131.2 +/- 22.7 pg/mL, respectively) than in those who did not present with pre-eclampsia at follow-up (n = 40; activin A: 1.79 +/- 0.18 ng/mL and inhibin A: 91.9 +/- 6.2 pg/mL; P < 0.05). Activin A at the cut-off value of 1.7 multiples of the median (MoM) achieved a sensitivity of 61% and a specificity of 89%, whereas inhibin A at the cut-off value of 1.8 MoM combined a sensitivity of 39% with a specificity of 92% for prediction of pre-eclampsia. The probability of pre-eclampsia was 31% in the whole study population, 86% if both activin A and inhibin A were elevated and 17% if both hormone markers were unaltered. CONCLUSION: The measurement of serum activin A and inhibin A levels may add significant prognostic information for predicting pre-eclampsia in pregnant women showing specific Doppler alterations in the late second trimester