In this post, I link to and excerpt from False-Negative Urine Human Chorionic Gonadotropin Testing in the Clinical Laboratory [PubMed Abstract] [Full-Text HTML] [Full-Text PDF]. Lab Med. 2020 Jan 2;51(1):86-93. doi: 10.1093/labmed/lmz039.l
All that follows is from the above resource.
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.