Falsely Decreased Human Chorionic Gonadotropin (hCG) Results Due to Increased Concentrations of the Free β Subunit and the β Core Fragment in Quantitative hCG Assays

Abstract

Extremely high concentrations of hCG variants can cause falsely decreased results in certain quantitative hCG assays. Of the 9 assays examined, none exhibited falsely decreased results in the presence of hCGβ concentrations typically associated with hCGβ-producing malignancies. Two assays exhibited decreased (>50%) hCG results in the presence of hCGβcf concentrations found during normal pregnancy.