Objective
To predict first trimester pregnancy outcome using biomarkers in a multicenter cohort. Design: Case-control study. Setting: Three academic centers. Patient(s): Women with pain and bleeding in early pregnancy. Intervention(s): Sera from women who were 5-12 weeks' gestational age with ectopic pregnancy (EP), viable intrauterine pregnancy (IUP), and miscarriage/spontaneous abortion (SAB) was analyzed by ELISA and immunoassay for activin A, inhibin A, P, A Disintegrin And Metalloprotease-12, pregnancy-associated plasma protein A (PAPP-A), pregnancy specific B1-glycoprotein (SP1), placental-like growth factor, vascular endothelial growth factor, glycodelin (Glyc), and hCG. Classification trees were developed to optimize sensitivity/specificity for pregnancy location and viability. Main outcome measure(s): Area under receiver operating characteristic curve, sensitivity, specificity, and accuracy of first trimester pregnancy outcome. Result(s): In 230 pregnancies, the combination of trees to maximize sensitivity and specificity resulted in 73% specificity (95% confidence interval (CI) 0.65-0.80) and 31% sensitivity (95% CI 0.21-0.43) for viability. Similar