The role of DNA strand breaks in human spermatozoa used for IVF and ICSI

Abstract

DNA strand breaks in human spermatozoa impairs fertilization in both unexplained infertile couples and those with oligozoospermia and IVF. However, after ICSI, this impact of DNA strand breaks were not seen. This creates a specific indication and treatment for this new diagnosed group of otherwise unexplained infertile men.

Mammalian sperm chromatin structure and assessment of DNA fragmentation

“…This labelling technique eliminates the problems associated with fluorescence fading in the microscopic method, thereby giving operators more time to analyze a greater number of cells for more accuracy [95][96][97][98]. Regarding use of light microscopy, some of the results reported based on this non-fluorescent technique confirm the results based on fluorescent TUNEL labeling techniques, other results seem to contradict previous findings [97][98][99][100][101].…”

Is sperm dna damage associated with IVF embryo quality? A systematic review

“…The 8 IVF study characteristics are depicted in Table 1. Of these 8 studies, 6 were reportedly prospective [6,21,26,27,30,50] but sampling was consecutive in only 1 paper [27]. Three studies excluded couples with poor ovarian reserve or advanced maternal age [21,30,50].…”

“…Of the 12 ICSI studies, 10 were reportedly prospective [2, 6, 22, 25-27, 30, 34, 37, 55] but sampling was consecutive in only 2 papers [27,55] (see Table 2). Three studies excluded couples with poor ovarian reserve or advanced maternal age [30,34,55].…”

DNA damage to spermatozoa has impacts on fertilization and pregnancy

“…However, this is not consistently the case with ICSI; with this technique, successful fertilization is not disrupted by high levels of DNA damage in the injected spermatozoa, regardless of whether ejaculated or testicular spermatozoa are used during therapy (Sun et al 1997;Hammadeh et al 1998;Lopes et al 1998;Twigg et al 1998;Esterhuizen et al 2000;Host et al 2000;Lewis et al 2004;Aitken 2004). This might be expected since, with ICSI, fertilization does not depend on the functional competence of the spermatozoa in terms of the ability of these cells to capacitate, to undergo the acrosome reaction, to penetrate the zona pellucida or to fuse with the vitelline membrane of the oocyte.…”