Maternal serum activin-A at 30-33 weeks in the prediction of preeclampsia

Objective: To investigate the potential value of maternal serum concentration of activin-A at 30-33 weeks' gestation in the prediction of preeclampsia (PE) developing at or after 34 weeks. Methods: Serum concentrations of activin-A were measured at 11-13 and at 30-33 weeks' gestation in a case-control study of 50 cases that developed PE and 250 unaffected controls. The measured values of activin-A were converted into multiples of the unaffected median (MoM), after adjustment for maternal characteristics, and the MoM values in the PE and controls were compared. Results: The median activin-A MoM at 30-33 weeks was higher in the PE group (1.47, IQR 1.14-2.38 versus 0.99, IQR 0.72-1.42), but at 11-13 weeks there was no significant difference between the groups. In screening by a combination of maternal characteristics and activin-A at 30-33 weeks the detection rate of PE was 50.0%, at a false positive rate of 10%. Conclusion: Screening by maternal characteristics and activin-A at 30-33 weeks could identify half of the pregnancies that will subsequently develop PE.