[A study on correlation between sperm DNA fragmentation index and age of male, various parameters of sperm and in vitro fertilization outcome].

Objective To study the correlation between sperm DNA fragmentation index (DFI), age of male, various parameters of sperm, rates of fertilization, high quality embryo and pregnancy and implantation rates. Methods One hundred and eleven infertile couples were selected randomly, and DFI was tested by flow cytometry for the sperm used for IVF. The patients were divided into different groups according to the DFI scores. The results of each group were analyzed. Results The IVF normal fertilization was significantly lower in couples with sperm DFI over 10% (60. 5%) than that in couples with DFI below 10% (70. 1%) (P＜0. 05). Significantly positive correlation was found between DFI and the age of male (r=0. 624, P＜ 0. 05). DFI was also significantly negatively correlated with the percentage of linearly progressive sperm (r=-0. 360, P＜0. 05). There was no significant correlation between the rates of high quality cleaved embryos, pregnancy and implantation rate and sperm DFI. Conclusion DFI scores are increased with male's age, and it can influence the sperm motility. DFI= 10% can be considered as a critical point which can be used to estimate the clinical fertility rate of IVF. But it could not provide relative information about the rates of high quality embryos and pregnancy for infertile couples undergoing IVF procedure. Key words: sperm;  DNA fragmentation index;  in vitro fertilization