CLINICAL-SIGNIFICANCE OF HUMAN SPERM-ZONA PELLUCIDA BINDING

Objective: To assess the relationship between sperm morphology and mot ion parameters and sperm-zona pellucida (ZP) binding capacity under he mizona assay (HZA) conditions and to determine the discriminatory powe r of the HZA for the prediction of in vitro sperm fertilizing ability. Design: Prospectively designed study. Setting: Academic tertiary cent ers. Patient(s): One hundred ninety-six couples undergoing IVF therapy participated in this study. Intervention(s): Hemizona assay and IVF r esults were determined for each couple. Main Outcome Measure(s): Compu terized sperm motion analysis, sperm morphology (strict criteria), and HZA results were correlated with fertilization outcome.Result(s): Amo ng sperm parameters from the original ejaculates, morphology was the b est predictor of sperm-ZP binding ability; hyperactivated motility was the best predictor of HZA results after swim-up separation of the mot ile sperm fractions. The HZA index provided the highest discriminatory power for fertilization success/failure, with an overall accuracy of 86%. Conclusion(s): Sperm morphology and hyperactivated motility showe d a high correlation with the capacity of sperm to achieve tight bindi ng to the ZP. The excellent positive and negative predictive values of the HZA for fertilization outcome provide additional support for the use of this functional bioassay in the decision-making process within the assisted reproduction setting. (C) 1997 by American Society for Re productive Medicine.