RESUMO
BACKGROUND: The dipstick methodology is the most fundamental urinalysis but interfered by many factors. We evaluated the effect of semen contamination on the urine dipsticks. METHODS: Thirty-two specimens for semen analysis were enrolled. After semen was directly applied on urine dipsticks, residual samples were diluted in pooled normal urine. Urine dipsticks were performed at each dilution titer. Seminal plasma separated by centrifugation of semen were also tested in the same manner. RESULTS: All semen showed positive results for blood, protein and leukocytes. The intensities of reaction for blood and leukocytes were correlated with sperm concentration. The negative conversion of blood and protein occurred at 1:100, and that of leukocytes occurred at 1:50. Seminal plasma showed nearly the same findings. CONCLUSIONS: Semen contamination of urine may cause false positive reaction especially for blood and protein on the urine dipsticks. It should therefore be considered when assessing unexplained, transient hematuria or proteinuria.