Intracytoplasmic sperm injection (ICSI) is a better choice than conventional in vitro fertilization (IVF) in assisted reproduction cycles with elevated sperm DNA fragmentation

Abstract

Many studies have shown a strong correlation between sperm deoxyribonucleic acid (DNA) fragmentation and cycle outcome in couples undergoing assisted reproduction technologies (ART). However, there is no agreement on whether IVF or ICSI provide a better chance for the couples when sperm DNA fragmentation is abnormally high (20%), although the other seminal parameters are normal. The aim of this study is to evaluate the sperm DNA integrity by comparing the rate of sperm DNA fragmentation in semen samples from infertile men and their fertilizing capacity and implantation rates in both conventional IVF and ICSI procedures. Prospective study of 45 couples from our laboratory IVF/ICSI program (from January 2006 to October 2006). We analyzed 45 couples that underwent a combined IVF/ICSI cycle after 4 failed intrauterine inseminations (IUI). Half of the retrieved oocytes from each couple were fertilized by ICSI and the other half by conventional IVF. After density gradient, sperm DNA fragmentation was measured by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling assay (TUNEL) with flow cytometry. Sperm DNA fragmentation was considered abnormal if values were >20%. Out of the 45 couples evaluated, 13 (29%) had an abnormal sperm DNA fragmentation test results. Fertilization rate with IVF was significantly reduced when compared with ICSI in these patients showing a high sperm DNA fragmentation (51% vs. 74%, P=0.027). Similarly, mean number of good quality embryos available for transfer in couples with high sperm DNA fragmentation was higher after ICSI (1.45 ± 0.7 vs. 0.85 ± 0.6, P=0.043). No significant differences were found in both implantation and pregnancy rates. Our results suggest that ICSI may be a better option than conventional IVF for those couples undergoing ART and showing an abnormally high sperm DNA fragmentation.