Relationship between zona pellucida-induced acrosome reaction, sperm morphology, sperm-zona pellucida binding, and in vitro fertilization

Objective: To evaluate the possible relationships between sperm morphology, acrosome responsiveness to solubilized human zona pellucida, and sperna-zona binding potential among [1] consecutive andrology referrals and [2] randomly selected in vitro fertilization (IVF) cases. Design: Prospective analytical study. Setting: Academic training hospital. Patient(s): Randomly selected couples consulting for infertility. Intervention(s): Acrosome reaction response to solubilized human zona pellucida was recorded. Main Outcome Measure(s): We determined the difference in the percentage of sperm that acrosome reacted after exposure to solubilized zona pellucida and spontaneous acrosome reaction. The results were expressed as percentage zona induced acrosome reaction (ZIAR). Result(s): Data were analyzed using correlation coefficients (r) and receiver operator characteristics (ROC curve analyses). The ROC curve analyses indicated ZIAR to be a sensitive indicator for fertilization failure during IVF therapy, with sensitivity and specificity of 81% and 75%, respectively. For andrology referrals, a positive and statistically significant correlation existed between ZIAR data and sperm morphology (r = 0.65) and sperm-zona binding (r = 0.57). Conclusion(s): ZIAR results provide further information regarding dysfunctional sperm and can be used as an additional diagnostic test. Our results predicted fertilization failure during IVF treatment.