High percentage of abnormal semen parameters in a prevasectomy population

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.