Factors affecting the variability of semen analysis results in infertile men.

Unlabelled: Infertile men who had 3 or more semen analyses performed in one laboratory were placed in 2 groups (I) oligozoospermic group (n = 106), mean sperm concentration between 1 and 20 million/ml (II) asthenozoospermic group (n = 71), mean sperm concentration greater than 20 million/ml, and mean motility less than 60%. With increasing durations of abstinence from ejaculation before the tests there were significant increases in semen volume and sperm concentration. Semen volume increased over the first 4 days to a similar extent in both groups.