Diagnostic Characteristics of Urine Microscopy in Detecting Asymptomatic Bacteriuria of Pregnancy Using Urine Culture as Gold Standard.

Abstract

Objective: The objective of the study was to evaluate the diagnostic characteristics of urine Microscopy in detecting asymptomatic bacteriuria of pregnancy . Methods: It was a descriptive, cross-sectional study involving 240 pregnant women who presented in the course of antenatal care from January to April 2009. With the aid of a questionnaire patients who were recruited for the study had their socio-demographic data and relevant gynaecological and drug history recorded. A physical examination was done to document temperature, height, weight and symphysiofundal height. A clean-catch mid-stream urine sample was collected for microscopy and culture. White blood cell count of ≥ 5/hpf and/or bacteria count of ≥ 1/hpf of urine was considered significant for urine microscopy and a single colony count of ≥10 5 / ml from two consecutive urine samples was considered significant for urine culture. Results: Using urine culture as gold standard, the sensitivity of urine microscopy was 90.9%, the specificity was 49.3%, the positive predictive value was 22.2% and the negative predictive value was 97.1%. Conclusion:Specificity of urine microscopy is very low. However, its high negative predictive value makes urine microscopy useful in ruling out bacteriuria in resource-poor settings.