OC13.04: The value of activin B and fibronectin as biomarkers to predict outcome in pregnancies of unknown location and viability at 11–14 weeks' gestation. (September 2016) - Al‐Memar, M.; Bobdiwala, S.; Saso, S.; Madhra, M.; De Cock, B.; Van Calster, B.; Brown, J.; Bottomley, C.; Papageorghiou, A.T.; Timmerman, D.; Horne, A.; Bourne, T.