Cryopreservation triggers DNA fragmentation and ultrastructural damage in spermatozoa of oligoasthenoteratozoospermic men

Objective: Oligoasthenoteratozoospermia (OAT) is one of the causes of male infertility. Cryopreservation is valuable for the management of infertility. This study aimed to reveal the effects of cryopreservation on sperm motility, morphology, ultrastructural details and DNA fragmentation in patients with OAT. Materials and Methods: In this observational study, ejaculates were collected from 40 male volunteers of whom 20 were OAT and 20 were normospermic. The ejaculates were stored in liquid nitrogen at -196 degrees C and analysed following thawing after 1 or 3 months. Ejaculates were evaluated in terms of motility, morphology and DNA fragmentation before and after thawing. Results: Sperm motility and morphology were both affected by cryopreservation in samples from both groups. After thawing, spermatozoa with morphological abnormalities were increased significantly in both groups. Ultrastructural investigations showed alteration in integrity of the membranes and increased acrosomal defects. Post-thaw investigations revealed prominent increases in the number of DNA fragmented cells in both groups when compared to the results before freezing. OAT groups revealed a significantly higher number of DNA fragmented spermatozoa compared to the normospermic group for both time periods. Conclusion: Cryopreservation produces ultrastructural damage and induces DNA fragmentation in both normospermic and OAT groups. The damage is more severe in the OAT group