Sperm nuclear DNA damage: update on the mechanism, diagnosis and treatment.

Previous studies have shown that repeated intracytoplasmic sperm injection failures can be associated with sperm DNA damage. This paper reviews the current understanding of the mechanism of sperm DNA damage, discusses different diagnostic methods and their threshold values to discriminate between good- and poor-prognosis patients, and outlines the currently available treatment options. A rational approach to the interpretation of sperm DNA fragmentation data and to the choice of the optimal treatment method is suggested.