Qualitative point-of-care human chorionic gonadotropin testing: can we defuse this ticking time bomb?

Abstract

Qualitative point-of-care (POC)2 human chorionic gonadotropin (hCG) testing is routinely performed on urine samples obtained in the Emergency Department (ED) or before surgery to rule out pregnancy and prevent fetal injury or death. Because potentially harmful treatments are allowed to proceed on the basis of a negative hCG test result, false-negative results can have disastrous consequences. We recently evaluated the performance of 11 common qualitative POC hCG devices and determined that 9 of the 11 devices were susceptible to false-negative results caused by hCG β core fragment (hCGβcf) (1). Although that study highlighted important limitations of these devices in a research laboratory setting, it was unclear whether users experience false negatives in clinical practice. We performed a search of the FDA's Manufacturer and User Facility Device Experience (MAUDE) database using the search term “MAUDE pregnancy false negative” (2). Our findings are shown in Figure 1. Seven hundred seven reports described false-negative POC hCG results in women shown to be pregnant at the time of testing. Ninety-one different POC hCG devices were described from 14 manufacturers, including 10 of the 11 devices evaluated in our initial screening study. Fig. 1. Results from a search of the FDA's MAUDE database with the search term “MAUDE pregnancy false negative”. 1 Search performed September 2, 2014. 2 Determined to be false-negative POC hCG results in women found to be pregnant at the time of testing or who were later shown to be pregnant by ultrasound or quantitative serum hCG measurement. 3 Not applicable due to false-positive result with a qualitative hCG device; false-negative result with other type of (non-hCG) device; false-positive or -negative result with a quantitative serum hCG device. 4 Several MAUDE reports documented false-negative results in multiple patients, resulting in a larger number of patients affected than number of reports. 5 Probable limit of detection was defined as last menstrual period 4–6 weeks before false-negative test; gestational age 4–6 …