P-19: Effect of Three Sperm Preparation Methods on Sperm DNA Integrity and Oocyte Fertilization Rate

Background: Techniques of sperm preparation require centrifugation to separate spermatozoa from the seminal plasma. The centrifugation can induce damage to the spermatozoa and increase reactive oxygen species(ROS) productionspecially in leukospermic speciemens that are associated with impaired function and fertilizing capacity. However in ICSI, fertilization can occure with damage DNA sperm but normal sperm chromatin strcture has been directly correlated with the rate of oocyte fertilization and embryo development. Our aim is to compare the effect of Swim up, DGC (with centrifugation) and Swim out (without centrifugation) techniques on spem DNA integrity by sperm chromatin dispersion (SCD) test and the fertilization rate. Materials and Methods: Semen sample was obtained from 207 patients referring to Montaserieh fertility and infertility center. 75 patients had leukospermia (>5×106 Not/ml) . Semen was analysed according to World Health Organization (WHO) criteria. Each semen sample was divided into 4 equal portions (Raw, Swim up, DGC, Swim out). Aliquots of each semen samples was measured for DNA fragmentation by SCD test. A total of 1863 oocytes were retrieved from patients and were injected with the husbands٫ prepared sperm. Then fertilization rate was evaluated on pronuclei stage. Results: For 207 patients, the level of DNA fragmentation in recovered sperms by 3 preparation methods was significantly lower than Raw semen (p<0.05). There was no significant difference in the percentage of DNA fragmentation and fertilization of recovered sperms by each of 3 methods(p>0.05). For 75 leukospermic patients, sperm DNA fragmentation after 3 methods was improved significantly compared with Raw semen. Sperm DNA fragmentation and fertilization rate significantly augmented in comparison with DNA integrity and Swimed up recovered sperms (p<0.05). Conclusion: Detrimental effect of sperm preparation techniques on sperm DNA fragmentation is related to the initial semen quality. It seems that use of Swim out method in leukospermic patients due to elimination of centrifugation step, which could stimulate ROS production by leukocytos can separate sperm with higher DNA integrity and increases fertilization rate.