The level of peripheral blood β-hCG concentration is inconsistent with the clinical manifestations of pregnant women: a cautionary tale

Abstract

As of September 2024, 964 clinical laboratories in China have achieved ISO 15189 accreditation, demonstrating their adherence to internationally recognized standards in quality, technology, and management. However, in one such ISO 15189-accredited laboratories, discrepancies arose between β-human chorionic gonadotropin (β-hCG) test results and the clinical manifestations of pregnant women, following a change in the reagent batch number. An investigation revealed that although the laboratory had established internal quality control (IQC) procedures and performance verification protocols for reagents and consumables for β-hCG testing, and monitored the ongoing validity of test results according to established standards, the IQC sample concentrations of the IQC sample did not encompass the ‘threshold’ required for the automated dilution detection of the testing system, the IQC procedure could not effectively assess the accuracy of high-concentration β-hCG samples, failing to detect whether the automated dilution procedure was functioning correctly. More concerningly, after the β-hCG test results for high-concentration specimens in the laboratory falsely decreased, laboratory personnel failed to promptly recognize the inconsistency between the test results and the clinical manifestations of the pregnant women. This issue was only recognized after 4 days, when it was raised by the requesting doctor. Therefore, we present this case to as a cautionary example for quality management in other clinical laboratories. Laboratories should focus on the quality risks associated with the automated dilution procedure in testing systems and are advised to monitor system performance by retesting patient samples and developing IQC materials.