Mammalian fertilization involves the direct in-teraction of the sperm and oocyte, fusion of the
cell membranes, and union of male and female gamete genomes. 1 The completion of this
process and subsequent embryo development depend in part on the inherent integrity of the
sperm DNA. 2 A threshold of sperm DNA damage (ie, DNA fragmentation, abnormal
chromatin packaging, protamine deficiency) appears to exist beyond which fertilization and
embryo development are impaired. 2, 3 Clinical evidence has now shown that human sperm …