title: Low accuracy of manual white blood cell count in amniotic fluid.
abstract: Intra-amniotic infection (IAI) is a common cause of pre-term labour. Manual WBC count on amniotic fluid (AF) has been suggested as a diagnostic test for IAI using a threshold of 50 cells/mm(3). However, no validation studies assessing the accuracy of this method have been performed. AF samples were selected for cell count analysis. WBCs were introduced to 47 AF samples. The results from two technologists' counts were compared with the calculated expected value for WBCs in these samples. Results showed that a comparison between the technologists' WBC count to the expected WBC count yielded R(2) coefficients of 0.62 and 0.78, indicating moderate accuracy. Percentage agreement between the technologists was 67%, indicating low reproducibility. It was concluded that there was moderate correlation between the manual and the expected WBC in the spiked AF samples. Clinicians should be aware of the inaccuracy and imprecision associated with this test when evaluating a patient for IAI.
authors: Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY, USA. emm9030@nyp.org
authors: E
authors: E
authors: McMillen
authors: J
authors: J
authors: Bautista
authors: A
authors: A
authors: Sireci
authors: A
authors: A
authors: Kratz
authors: B
authors: B
authors: Stotler
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology*; D002821:Chorioamnionitis / Q000175:diagnosis* / Q000276:immunology; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000592:standards*; D011247:Pregnancy