Objective: To evaluate semen characteristics, testicular volume, and hormonal levels of normal fertile men requiring vasectomy for sterilization.
Design: Retrospective study.
Setting(s): Academic medical centers.
Patient(s): A total of 889 patients underwent a vasectomy for sterilization.
Intervention(s): None.
Main outcome measure(s): Semen volume, sperm concentration, motility, and morphology according to the World Health Organization (WHO); complex motion parameters evaluated by computer-assisted semen analyzer; FSH, LH, and T levels; and both testicular volumes.
Result(s): When compared with the WHO values, 87.2% of the patients presented normal sperm morphology below the normal level. The other semen parameters (semen volume, pH, sperm concentration, and sperm motility) differed from the WHO parameters in 6%-32.2% of patients. Semen volume and sperm concentration presented a progressive increase according to the duration of sexual abstinence. However, patients with 5 days or more of abstinence had a decrease in sperm motility. Mean testicular size had the strongest correlation with serum FSH levels, total sperm count, and sperm concentration.
Conclusion(s): Low sperm motility and morphology were found in men who request a vasectomy for sterilization. Semen volume and sperm concentration present a progressive increase and sperm motility a decrease according to the duration of sexual abstinence. Sperm concentration had stronger correlations with testicular size than did sperm quality. Therefore, the WHO normal values need to be reconsidered.