Morphology and the sperm penetration assay

Objective: To assess the ability of Kruger morphology to predict the outcome of the sperm penetration assay (SPA). Design: A retrospective review using univariate and multivariate analysis, t tests, and logistic regression was performed to examine the correlation between Kruger morphology and the optimized zona-free hamster egg sperm penetration assay (O-HESPA). Setting: University hospital. Patient(s): One hundred fifteen private-practice patients who underwent semen analysis, including Kruger morphology and O-HESPA, as part of an infertility evaluation between 1997-2000 were retrospectively reviewed. Intervention(s): Retrospective analysis of the sperm penetration assay. Main outcome measure(s): Univariate and multivariate analysis, Student's t test, and logistic regression were performed to analyze Kruger morphology, count, and viability and their relationship to SCI result. Result(s): Univariate analysis demonstrated a statistically significant correlation between SCI and sperm count, viability, and Kruger morphology. Multivariate analysis demonstrated statistically significant correlations between SCI and count and viability. There was no correlation between Kruger morphology and SCI. Logistic regression was performed on the SCI results, using count, Kruger morphology, and viability. Sperm count was found to be the only variable that was statistically significant with respect to SCI results. Conclusion(s): This study demonstrated that Kruger morphology assessment cannot be used to predict the results of SCI or replace it in the management of the infertile couple.