Effects of abnormal structure of sperm chromatin on the outcome of in vitro fertilization and embryo iransier

Objective To explore the effects of sperm chromatin structure abnormalities on the outcome of in vitro fertilization and embryo transfer (IVF-ET). Methods Sperm DNA fragmentation and chromatin packaging defects were assessed in 136 couples undergoing IVF-ET because of infertility. The relationship between sperm DNA fragmentation, chromatin packaging defects and fertilization rate and clinical pregnancy was evaluated. Results Both sperm DNA fragmentation and chromatin packaging defect had a negative correlation with fertilization rate (r= -0. 198, P＜0. 05, and r= -0. 389, P＜0. 01,respectively). Both parameters were higher in couples who failed to achieve pregnancy than those who achieved clinical pregnancy (10. 74% vs. 5. 40%, P＜0. 01 and 23. 58% vs. 11. 83%, P＜0. 01,respectively). Conclusion Abnormality of sperm chromatin structure is one of the reasons for IVF-ET failure. Examination of sperm chromatin structure is helpful in predicting he risk of IVF-ET failure and optimizing treatment of infertility. Key words: infertility;  in vitro fertilization;  embryo transfer;  spermatozoa;  chromatin