Investigating the effect of polyvinylpyrrolidone-based urinary catheter coatings on spermatozoa quality

Objectives Hydrophilic-coated intermittent urinary catheters containing polyvinylpyrrolidone (PVP) are used to alleviate chronic urinary retention in individuals with neurogenic bladder dysfunction, most notably spinal cord injury (SCI) patients. However, coating delamination during catheterisation can leave PVP coating residues within the urethra, which may accumulate due to frequent catheterisation and loss of natural urethral flushing. PVP is employed in intracytoplasmic sperm injection to reduce spermatozoa motility, and prolonged exposure can alter spermatozoa morphology. Despite the high prevalence of infertility in SCI patients, the impact of PVP catheter coating residues on sperm function has not previously been explored. Methods This study examined coating delamination from four commercial PVP-coated catheters using an ex vivo porcine urethral model, followed by exposure of porcine spermatozoa to PVP residues. Spermatozoa viability, morphology, motility, and chromatin integrity were assessed. Key findings PVP coating residue exposure significantly reduced motility in porcine spermatozoa, with progressive movement falling below the threshold for human fertilisation. Morphological abnormalities were observed in the head, midpiece, and tail, while chromatin integrity analysis revealed minimal fragmentation. Conclusions These findings suggest that PVP coating residues can impair spermatozoa motility and morphology through physical interactions with PVP rather than genotoxic damage. If these findings in a porcine model translate to humans, they may potentially exacerbate fertility challenges in male SCI patients reliant on intermittent catheterisation.