title: False-positive urine pregnancy tests--clinicians as detectives.
abstract: Reliably diagnosing pregnancy in women presenting with nonspecific abdominal pain can be lifesaving. If diagnostic tests are unreliable, however, valuable time and resources can be wasted pursuing unnecessary and potentially harmful interventions. After four false positive-urine pregnancy tests in one week, we began investigating the laboratory's entire process involving the UPreg tests. We discovered that, as is common in resource-poor settings, the laboratory repeatedly reused test tubes. We found that the false-positive tests resulted from performing the UPreg tests in test tubes that were improperly cleaned and, for the most part, had been used immediately beforehand to test women coming into the maternity ward. Sufficient residua from the pregnant women's high ß-HCG levels had remained in the test tubes to cause subsequent false-positive results in our emergency ward patients. Although pregnancy can now be reliably diagnosed with inexpensive, disposable and simple tests, these tests must not only be used properly, but also, when used in the laboratory, be accompanied by appropriate cleaning and quality-control procedures. This is particularly essential in resource-constrained environments.
authors: Department of Emergency Medicine, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA.
authors: Rolando
authors: R
authors: Valenzuela
authors: Kenneth V
authors: KV
authors: Iserson
authors: Damien
authors: D
authors: Punguyire
mesh_terms: D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000032:analysis*; D004866:Equipment Contamination; D017743:Equipment Reuse; D004865:Equipment and Supplies, Hospital / Q000592:standards*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D011247:Pregnancy; D011258:Pregnancy Tests / Q000592:standards*
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human