False-Negative Urine Human Chorionic Gonadotropin Testing in the Clinical Laboratory

Lab Med. 2020 Jan 2;51(1):86-93. doi: 10.1093/labmed/lmz039.

Abstract

Background: Human chorionic gonadotropin (hCG) assays are used to detect pregnancy, and urine point-of-care tests are frequently used to triage patients. Under certain conditions, urine tests can fail to detect pregnancy, which can have serious consequences for patient management.

Objectives: To understand the prevalence of different factors contributing to false-negative urinary hCG testing results at our institution.

Methods: Clinical data for patients with negative urine hCG results and subsequent positive or equivocal serum hCG results within a 1-year period were reviewed.

Results: Out of 9447 negative urine hCG results, 11 potential missed diagnoses were identified, with early gestational age as the most common factor, followed by β-core hook effects.

Conclusions: Although false-negative urine hCG test results are rare, understanding the commonly encountered reasons for inaccurate testing results can help clinical centers develop strategies to minimize risk for patients.

Keywords: early gestational age; human chorionic gonadotropin; point of care; pregnancy; serum hCG; urine hCG.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Biomarkers / blood
  • Biomarkers / urine
  • Chorionic Gonadotropin / blood
  • Chorionic Gonadotropin / urine*
  • Clinical Laboratory Services / standards
  • Clinical Laboratory Services / statistics & numerical data
  • False Negative Reactions
  • Female
  • Humans
  • Point-of-Care Systems
  • Pregnancy Tests / methods
  • Pregnancy Tests / standards*

Substances

  • Biomarkers
  • Chorionic Gonadotropin