Analysis of semen parameters during 2 weeks of daily ejaculation: a first in humans study.

BACKGROUND: Timed and frequent intercourse around the time of female ovulation is recommended to improve conception. Although a significant number of articles have examined how the length of abstinence affects these semen analysis, the effects of frequent (daily) ejaculation has not been rigorously studied.

METHODS: Twenty normal men were recruited for daily ejaculation over 14 consecutive days, after a 3-5 days abstinence period. Semen samples were collected at the beginning of the study (day 1) and then on days 3, 7 and 14. In addition to the standard semen analysis, markers of sperm DNA quality were assessed.

RESULTS: The mean age of men completing the study was 25 years (range, 23-33 years). Significant decreases were observed in mean semen volume, total motile count (TMC) and sperm concentration during the study period without significant changes in motility or morphology. A large initial change in ejaculate volume, TMC and sperm concentration provided the primary difference in these values over the study period, with a plateau in values after this initial decrease (after study day 3). Metrics of DNA integrity did not change in a statistically or clinically meaningful way during the study period.

CONCLUSIONS: While a small study, this represents the most extensive examination of sperm quality with daily ejaculation. These findings generally support an approach of a short period of abstinence followed by daily copulation around ovulation to maximize the number of sperm available and optimize conception.