Clinical value of sperm DNA damage should be assessed in motile sperm fraction rather than whole ejaculated sperm

ObjectiveTo determine differences and frequency of excessive (≥50%) sperm DNA damage between ejaculated and motile sperm.DesignSperm DNA damage was assessed by acridine orange fluorescence and the results of ejaculated and motile sperm were compared.SettingPublic and private clinical assisted reproduction centers.Patient(s)A total of 272 subfertile men were studied.Intervention(s)None.Main Outcome Measure(s)Semen analysis and sperm DNA damage.Result(s)Sperm DNA damage was negatively correlated with sperm motility and normal morphology. Overall, 39.7% (108 of 272) of semen samples had excessive sperm DNA damage. In contrast, only 15% (41 of 272) of motile sperm fractions had excessive DNA damage. Based on DNA results of motile sperm and semen characteristics, the proportion of men with excessive sperm DNA damage was 26% in severe teratozoospermia, 17.5% in oligozoospermia, 12.5% in moderate teratozoospermia, and 4.6% in normozoospermia. Severe teratozoospermia had five times more frequent excessive DNA damage than normozoospermia.Conclusion(s)Abnormal sperm morphology is highly associated with sperm DNA damage. Results of DNA damage of ejaculated sperm do not accurately reflect DNA status of motile sperm. Therefore, sperm DNA damage should be assessed in motile sperm fraction rather than whole ejaculated sperm.