Time-to-Ejaculation and the Quality of Semen Produced by Masturbation at a Clinic.

OBJECTIVES: To investigate the association between the length of time-to-ejaculation and semen parameters. METHODS: Ejaculates from 142 men under infertility assessment were analyzed according to the World Health Organization guidelines. Seminal neutral alpha-glucosidase (NAG), prostate-specific antigen (PSA), zinc, and fructose were also measured. Three groups according to the length of the time-to-ejaculation were defined: G(<10) (<10 minutes), G(10-15) (10 to 15 minutes), and G(>15) (greater than 15 minutes). RESULTS: Time to ejaculation showed negative significant correlation with sperm concentration (rho = -0.20, P = 0.02), total sperm count (rho = -0.20, P = 0.04), NAG (rho = -0.20, P = 0.01), and fructose (rho = -0.30, P = 0.02), respectively. No significant correlations existed among the time-to-ejaculation and age, sexual abstinence, semen volume, sperm motility, PSA, and zinc. There were negative significant associations among time-to-ejaculation and sperm concentration (beta = -3.0; P = 0.004), total sperm count (beta = -10; P = 0.02), total count of progressive motility (beta = -7.0; P = 0.02), and fructose (beta = -0.30; P = 0.02), respectively. No significant associations existed among the time-to-ejaculation and semen volume, motility grades, NAG, PSA, and zinc. G(<10) was characterized by higher sperm concentration, total sperm count, and total count of progressive motility compared with G(10-15) (mean difference = 33 x 10(6)/mL; P = 0.01), (mean difference = 96 x 10(6)/ejaculate; P = 0.50), (mean difference = 77 x 10(6)/ejaculate; P = 0.02), respectively, and G(>15) (mean difference = 50 x 10(6)/mL; P = 0.01), (mean difference = 176 x 10(6)/ejaculate; P = 0.02), (mean difference = 110 x 10(6)/ejaculate; P = 0.03), respectively. Fructose was significantly higher in G(<10) compared with G(>15) (mean difference = 5.0 mmol/L; P = 0.03). CONCLUSIONS: The time-to-ejaculation length was associated with semen parameters. These results might reflect the negative effect of acute stress during semen collection via masturbation at a clinic on semen parameters.