Prediction of pre-eclampsia by uterine artery Doppler ultrasonography and maternal serum pregnancy-associated plasma protein-A, free β-human chorionic gonadotropin, activin A and inhibin A at 22 + 0 to 24 + 6 weeks' gestation
Spencer K., Yu CKH., Savvidou M., Papageorghiou AT., Nicolaides KH.