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Prediction of pregnancy complications by first-trimester maternal serum PAPP-A and free beta-hCG and with second-trimester uterine artery Doppler.
Spencer K, Yu CK, Cowans NJ, Otigbah C, Nicolaides KH.
Prenat Diagn 2005;25:949-53. -
First trimester maternal serum free beta human chorionic gonadotrophin and pregnancy associated plasma protein A as predictors of pregnancy complications.
Ong CY, Liao AW, Spencer K, Munim S, Nicolaides KH.
BJOG 2000;107:1265-70.