Frozen-thawed spermatozoa from oligozoospermic ejaculates are susceptible to in situ DNA fragmentation in polyvinylpyrrolidone-based sperm-immobilization medium

ObjectiveTo elucidate the effect of sperm immobilization media that are and are not based on polyvinylpyrrolidone (PVP) on the DNA integrity of fresh and frozen-thawed spermatozoa during standard intracytoplasmic sperm injection (ICSI) conditions.DesignExperimental prospective study.SettingEmbryology research laboratory.Patient(s)Forty-six ejaculates from normozoospermic and oligozoospermic men.Intervention(s)Assessment of sperm DNA fragmentation by single-cell gel electrophoresis assay.Main Outcome Measure(s)DNA integrity of fresh and frozen-thawed spermatozoa from normozoospermic and oligozoospermic ejaculates exposed to PVP-based and non-PVP-based media.Result(s)Exposure of fresh and frozen thawed spermatozoa from normozoospermic and oligozoospermic ejaculates to PVP-based medium in an ICSI dish for 30 minutes statistically significantly increased the DNA fragmentation. In contrast, the extent of DNA fragmentation in non-PVP-based medium did not statistically significantly differ from control.Conclusion(s)A PVP-based medium can induce a statistically significant amount of sperm DNA fragmentation in an ICSI dish, and frozen-thawed sperm from oligozoospermic ejaculates are more susceptible to in situ DNA fragmentation.