Normal range and variation of the zona pellucida–induced acrosome reaction in fertile men

Abstract

Objective To investigate the normal range of the zona pellucida (ZP)–induced acrosome reaction (AR) in fertile men. Design A study of normative data. Setting Academic research and teaching tertiary hospital. Intervention(s) None. Patient(s) Fertile men (n = 111) who had children or whose female partner was currently pregnant. Main outcome measure(s) Semen analysis, sperm–ZP binding, and the ZP-induced AR. Result(s) There was wide range for the ZP-induced AR: 20%–98% with a mean of 48%. The ZP-induced AR was significantly correlated with sperm concentration and normal morphology. The ZP-induced AR was significantly lower in men with sperm concentration ≤60 × 10 6/mL than those with sperm concentration >60 × 10 6/mL. Similarly, men with normal sperm morphology ≥15% had significantly higher ZP-induced AR than men with normal morphology <15%. Conclusion(s) There is a wide range of the ZP-induced AR in fertile men that is correlated with sperm concentration and normal morphology.