Abstract

Multiple measurements of serum human chorionic gonadotropin (hCG) are used to predict the final pregnancy outcome for women with a pregnancy of unknown location (PUL) and monitor the management of ectopic pregnancy (EP). Urine-based testing would be more convenient and economical. This prospective cohort study involving 80 women assessed the degree of correlation between serum and urine hCG levels and whether urine hCG levels have the potential to impact clinical decision making in the management of women with a PUL. Paired urine and serum hCG measurements differed quite widely but were well correlated and the degree of correlation improved after creatinine correction. Although serial serum hCG measurements appear to be better for the overall prediction of pregnancy outcome in PUL (AUC 0.77–0.94 compared to corrected urine AUC 0.69–0.84), serial urine hCG measurements may have a role in identifying subtypes of low-risk PUL (AUC 0.83–0.84).