Selection of sperm based on hypo-osmotic swelling may improve ICSI outcome: a preliminary prospective clinical trial

ABSTRACT

The intra-cytoplasmic sperm injection [ICSI] technique selects sperm according to morphology and motility. However, these parameters cannot predict the chromatin integrity of sperm. Considering the detrimental effects of DNA-damaged sperm on reproductive outcomes, novel sperm selection procedures have been proposed to circumvent the possibility of inseminating DNA-damaged sperm. It has been shown that different potential hypo-osmotic swelling test [HOST] patterns possess the potential to differentiate between sperm that have intact or damaged chromatin. Therefore, for the first time, this preliminary study evaluates the role of HOST as a sperm selection procedure in a clinical setting. In this preliminary prospective clinical trial study, we divided infertile couples diagnosed with male infertility into two groups. In the treatment group [n=39], half of the oocytes were inseminated by sperm selected following density gradient centrifugation [DGC group]. The remaining oocytes from the treatment group were inseminated by sperm chosen according to HOST pattern [c, d or e] following DGC processing [HOST group]. In the control group [n=63], all oocytes were inseminated by sperm chosen after DGC. There was a significantly higher percentage of embryos that had good quality, implantation, and chemical pregnancy rates in the HOST group compared to the DGC group [psperm according to membrane functionality [HOST pattern] rather morphology and viability may open a new window in our approach for determining the appropriate sperm for ICSI, particularly in individuals with severe male infertility