Density gradient centrifugation specifically improves sperm motility in hyperuricemia: evidence from intrauterine...

Hyperuricemia (HUA) impairs sperm function via oxidative stress and metabolic dysregulation. This retrospective cohort study aimed to investigate the therapeutic effect of density gradient centrifugation (DGC) on HUA-associated sperm dysfunction.

A total of 490 couples undergoing their first intrauterine insemination (IUI) were stratified into the HUA group (200 cycles) and control group (290 cycles) based on male serum uric acid levels. At baseline, the percentage of progressively motile sperm (PR%) in the HUA group was significantly lower than that in the control group (39.55% ± 11.29% vs. 41.76% ± 11.89%, P = 0.040). Following DGC processing, PR% in both groups exceeded 90% with no significant intergroup difference; however, the increase in PR% (ΔPR%) was significantly greater in the HUA group (52.34% ± 10.62% vs. 50.29% ± 11.02%, P = 0.040). No significant difference was observed in the clinical pregnancy rate between the two groups (11.0% vs. 13.4%, P = 0.230).

DGC specifically improves sperm motility in patients with HUA. While direct measurement of mechanistic markers (e.g., oxidative stress, metabolic factors) was not performed in this study, this motility-improving effect may correlate with DGC's known capacity to scavenge reactive oxygen species and optimize energy supply-an inference supported by prior mechanistic studies. However, improving sperm motility alone is insufficient to significantly enhance clinical pregnancy rates. These findings provide insights to optimize semen preparation strategies in HUA-associated male infertility.