A Comparison between Diagnostic Value of Pyuria and Bacteriuria in Asymptomatic Bacteriuria in Pregnant Women

Document Type : Original Article


1 Assistant professor, Department of Obstetrics & Gynecology, Tehran University of Medical Sciences, Tehran, Iran.

2 Associate professor, Department of Obstetrics & Gynecology, Tehran University of Medical Sciences, Tehran, Iran.

3 Resident, Department of Obstetrics & Gynecology, Tehran University of Medical Sciences, Tehran, Iran.


Introduction:This study was designed to Evaluate the diagnostic value of pyuria and bacteriuria in asymptomatic bacteriuria in pregnant women.
Methods:A cross sectional study was performed on 1246 pregnant women who were visited in a prenatal clinic without any urinary symptoms. For all of these women’s urinalysis (leukocyte count, bacteriuria) and urine culture, were performed. Then the patients were divided into the three groups: 1) the patients who had just pyuria in their urinalysis (≥5 WBC in HPF),2)The patients who had just bacteriuria in their urinalysis, 3). The patients who had both bacteriuria and pyuria. The positive urine culture was considered as gold standard. Positive urine culture was defined as growth of more than 105 of one kind of bacteria. Then the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were determined for the three groups using SPSS 16.
Results:There were 113 (9%) cases of positive culture and 222 cases of pyuria, bacteriuria or both. In patients with pyuria (78 cases), there were 34 (43.5%) cases of positive culture with the sensitivity of 86.9%, Specificity of 94.5%, PPV=57.7% and NPV=99.3%. In Patients with bacteriuria (73 cases), there were 27 cases of positive culture, with the sensitivity of 91.8%, specificity of 99.3%, PPV=54.8% and NPV=99.3%. In the third group (pyuria plus bacteriuria), (71 cases), 52 (73.2%) patients had positive culture. The sensitivity, specificity, PPV and NPV of test were 88.1%, 98.3%, 73.2% and 99.3%, respectively. There were 7 cases (0.5%) of positive culture without pyuria and bacteriuria.
Conclusion:The combination of pyuria and bacteriuria in urinalysis or pyuria with more than 10 WBC in HPF or many bacteriuria, have high sensitivity, specificity, NPV and PPV for the diagnosis of asymptomatic bacteriuria and can be a good substitute for urine culture and only 7.7% of patients need urine culture.


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