Abstract:

Objective  To explore the effects of cryopreservation on morphology, oxidative stress and DNA integrity of human sperm． Methods  According to World Health Organization criteria (1999 year), we chose 30 normal semen samples and 30abnormal semen samples. The sperm morphology, maleic dialdehyde (MDA) concentration and nuclear DNA integrity of the two groups were analyzed before and after freezing—thawing． Results  In the normal group, the freezing—thawing process significantly influenced sperm morphology and MDA concentration（P＜0.05）,　butthere was no significant difference compared with that before freezing in DNA integrity, and the results showed significant differences in sperm morphology, DNA integrity and MDA concentration between the fresh and frozen samples in the abnormalgroup（P＜0.05）; ②Compared with the normal group, cryopreservation caused significant differences in sperm morphology and DNA integrity in the abnormal group（P＜0.05）; ③Sperm morphology was negatively correlated with MDA concentration, and MDA concentration was positively correlated with DNA integrity(P＜0.05). Conclusion  Cryopreservation affects sperm morphology, DNA integrity and MDA concentration in abnormal semen, while it only affected sperm morphology and MDA concentration in normal semen.

Key words: Sperm cryopreservation； Reactive oxygen species； Oxidativestress； DNA integrity