Accuracy of serum beta-human chorionic gonadotropin cutoff values at 42 and 49 days' gestation.
D000032:Abortion, Therapeutic / Q000379:methods; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood* / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy / Q000097:blood*; D016016:Proportional Hazards Models; D012042:Registries; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal