Post-ejaculatory urinalysis in fertile and infertile men

Abstract

Objective: Standard criteria for the interpretation of a postejaculatory urinalysis (PEU) do not currently exist. The purpose of this study was to assess a population of fertile and infertile men in order to determine the prevalence of sperm within postejaculatory urine and develop a cutpoint for interpretation of this test.Design: Prospective, university-based study.Materials/Methods: Both semen analysis and postejaculatory urinalysis was performed upon 15 men undergoing elective vasectomy (fertile group) and 80 patients attending an infertility clinic (infertile group). The percentage of sperm present in the urine as compared to that in the semen was calculated. A variety of criteria for a positive PEU were assessed including any sperm present and various percentages of sperm in the urine. IRB approval was obtained for this study.Results: The mean age of the fertile men (37 years) was not different from the infertile patients (40 years). As expected, the median total sperm count of the fertile men (128 million) was significantly higher (p <0.001) than the infertile patients (8 million). The median total urine sperm count for the fertile group (26.6 million) was greater than the infertile group (2.5 million) but was not significantly different (p = 0.234). Using a cutpoint of the urine containing greater than 5% of the total semen sperm count, the prevalence of a positive PEU in fertile controls (60%) was no different from the infertile patients (50%). Similar findings were observed using all other cutpoints for a positive PEU. The median semen volume for men with a positive PEU (1.4 ml) was significantly lower than for those with negative PEU (2 ml) (p = 0.048).Conclusions: Although we ultimately chose 5% as the cutpoint for this study, a variety of criteria may be used to define a positive PEU. Whatever criteria are used, the prevalence of a positive PEU in the fertile population is similar to infertile patients suggesting that a great deal more information is needed to interpret this test in the management of these patients. Moreover, it is unclear from this study whether the sperm found in the urine is coming from the bladder urine or simply being washed out of the urethra.Supported by: U54 HD36209 from NICHD. Objective: Standard criteria for the interpretation of a postejaculatory urinalysis (PEU) do not currently exist. The purpose of this study was to assess a population of fertile and infertile men in order to determine the prevalence of sperm within postejaculatory urine and develop a cutpoint for interpretation of this test. Design: Prospective, university-based study. Materials/Methods: Both semen analysis and postejaculatory urinalysis was performed upon 15 men undergoing elective vasectomy (fertile group) and 80 patients attending an infertility clinic (infertile group). The percentage of sperm present in the urine as compared to that in the semen was calculated. A variety of criteria for a positive PEU were assessed including any sperm present and various percentages of sperm in the urine. IRB approval was obtained for this study. Results: The mean age of the fertile men (37 years) was not different from the infertile patients (40 years). As expected, the median total sperm count of the fertile men (128 million) was significantly higher (p <0.001) than the infertile patients (8 million). The median total urine sperm count for the fertile group (26.6 million) was greater than the infertile group (2.5 million) but was not significantly different (p = 0.234). Using a cutpoint of the urine containing greater than 5% of the total semen sperm count, the prevalence of a positive PEU in fertile controls (60%) was no different from the infertile patients (50%). Similar findings were observed using all other cutpoints for a positive PEU. The median semen volume for men with a positive PEU (1.4 ml) was significantly lower than for those with negative PEU (2 ml) (p = 0.048). Conclusions: Although we ultimately chose 5% as the cutpoint for this study, a variety of criteria may be used to define a positive PEU. Whatever criteria are used, the prevalence of a positive PEU in the fertile population is similar to infertile patients suggesting that a great deal more information is needed to interpret this test in the management of these patients. Moreover, it is unclear from this study whether the sperm found in the urine is coming from the bladder urine or simply being washed out of the urethra. Supported by: U54 HD36209 from NICHD.