Objective: To report the effects of ribavirin plus pegylated interferon on semen parameters and sperm DNA integrity in a man given treatment for hepatitis C.

Design: Case report.

Setting: University-affiliated teaching hospital.

Intervention(s): None.

Patient(s): A 37-year-old man given treatment with ribavirin and pegylated interferon for hepatitis C.

Main outcome measure(s): Semen parameters (sperm count, motility, round cells), sperm protamination state measured by sperm chromatin structure assay, and sperm DNA fragmentation measured by terminal uridine nick-end labeling assay.

Result(s): The percentage of progressive spermatozoa and the number of motile sperm per ejaculate decreased during treatment. The round cell/spermatozoa ratio, which reflects spermatogenic abnormality, increased from 2.6% +/- 1.4% to 23.6% +/- 13.0% during treatment and returned to baseline value 4 months later. Moreover, the sperm DNA fragmentation index (as measured by sperm chromatin structure assay) increased very markedly during treatment (from 14.5% before to 69.2% at 7 months of treatment) and remained elevated 8 months later.

Conclusion(s): This study reports for the first time not only quantitative but also qualitative alterations of spermatogenesis with DNA packaging abnormalities and emphasizes the need for prospective clinical studies. While the results of other studies are awaited, the alterations that persisted 8 months after treatment argue for a longer contraception period after treatment discontinuation in men.