Diagnostic performance of discontinuous density gradient centrifugation for estimating human semen quality

BACKGROUND: Semen analysis plays an important role in the diagnosis of male infertility. However, many studies have demonstrated that the current methods of semen analysis are inefficient for assessing male fertility. OBJECTIVE: To test whether prior discontinuous density gradient centrifugation (DDCG) improves the performance of semen analysis in diagnosing male infertility. MATERIALS AND METHODS: Infertile men and fertile men were recruited from the clinic. Pre- and post-DDGC values for the semen parameters of sperm concentration, total sperm number, percent total motility, percent progressive motility, percent normal sperm morphology, and sperm DNA fragmentation rate were compared. RESULTS: A total of 528 men (252 infertile men and 276 fertile men) were enrolled in the present study. After DDGC, sensitivity was significantly increased for sperm concentration, total sperm number, and sperm morphology (P < .01); specificity was significantly increased for progressive motility and sperm morphology (P < .01); and diagnostic accuracy was significantly improved for all of these parameters (area under the curve (AUC): P < .01). Total motility and sperm DNA fragmentation rate exhibited no obvious change in sensitivity, specificity or accuracy after DDGC (all P > .01). For the combination of all these semen parameters, diagnostic accuracy improved significantly after DDGC (AUC: P < .01). In a multiple regression analysis, only sperm morphology and sperm DNA fragmentation rate had P values less than 0.05 before DDGC, whereas all parameters except total sperm number contributed to the equation after DDGC. DISCUSSION: DDGC is a mature, standardized procedure for clinical commonly used to optimize spermatozoa. The diagnostic accuracy of semen analysis was significantly improved after DDGC, which indicated that assessing "functional spermatozoa" might be a more suitable method for semen analysis than the WHO 2010 criteria. CONCLUSION: Assessing semen parameters after DDGC might improve their diagnostic accuracy for male infertility.