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

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 less than or equal to 60 x 10(6)/mL than those with sperm concentration >60 x 10(6)/mL. Similarly, men with normal sperm morphology greater than or equal to15% 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. (C) 2003 by American Society for Reproductive Medicine.