Objective: To determine the influence of ejaculatory abstinence on within-subject semen parameters and DNA fragmentation.
Design: Prospective study.
Setting: Private infertility institute and university-based research laboratory.
Patient(s): Sixteen consenting male volunteers undergoing infertility investigation.
Intervention(s): None.
Main outcome measure(s): Within-subject analysis of World Health Organization semen parameters and sperm DNA fragmentation and chromatin packaging after 1, 3, 5, and 8 days' abstinence.
Result(s): Of 16 men recruited, data for 11 men were included for statistical analysis because 5 men did not strictly comply with abstinence criteria. Duration of abstinence had a statistically significant positive influence on sperm concentration and semen volume. Abstinence had no statistically significant influence on pH, viability, total and grade A motility, or morphology. The percentage of DNA fragmentation remained unchanged relative to abstinence. The percentage of sperm with immature chromatin was statistically significantly increased with 1 day of abstinence.
Conclusion(s): This is the first study to report on within-subject semen parameter, DNA fragmentation, and chromatin packaging variations after specified target days of abstinence. Sperm numbers and semen volume increased with duration of abstinence. Abstinence did not influence pH, viability, morphology, total or grade A motility, or sperm DNA fragmentation. A short (24-hour) abstinence period negatively influenced chromatin quality.