The effect of Swim-up and Gradient sperm preparation techniques on deoxyribonucleic acid (DNA) fragmantation

In this prospective study, we evaluated the impact of the two sperm washing techniques (swim-up and density gradient) on DNA fragmantation in couples who diagnosed with unexplained and mild male factor infertility. 34 unexplained infertility and 31 mild male factor infertility subjects were included in the study. There was a significant decrease in the percentage of DNA fragmentations before and after washing with swim-up method in the total study group (p=0,0001). Although the gradient technique decreased the DNA fragmentation rate (44,1±20,79 vs. 41,2±21,62) in the total group, the difference was not significant between before and after washing (p=0,129). In both of the infertility groups, there was a statistically significant decrease in the DNA fragmentation rates before and after washing with swim up technique (p<0,0001). Although the gradient technique decreased the DNA fragmentation in both groups, the difference was not significant between before and after washing (unexplained infertility: p=0.160 and male factor infertility p=0.470). When we compared the fragmentated DNA percentages of the two techniques before and after washing, sperm percentage with fragmentated DNA after swim-up technique was significantly lower than the gradient technique (p<0,0001). When we looked at the results of the patients with and without pregnancy after IUI, there was no statistically significant relationship between the percentages of progressive motil sperm and DNA fragmentation before and after washing. In conlusion, swim up technique seems to lower the DNA fragmentation more than gradient technique. Further studies in larger series would be useful to improve our understanding of the prognostic value of sperm DNA integrity to IUI outcome.