The significance of the ionophore-challenged acrosome reaction in the prediction of successful outcome of controlled ovarian stimulation and intrauterine insemination.

Background: This prospective study compared the acrosome reaction following ionophore challenge (ARIC) versus conventional sperm parameters and sperm velocities in predicting successful outcome following ovarian stimulation and intrauterine insemination.

Methods: All patients were offered a maximum of three treatment cycles. Conventional semen analysis was performed and sperm velocities were measured using computer-aided sperm analysis. Acrosome-reacted sperm were stained using chlortetracycline after ionophore challenge. Multiple logistic regression analysis and the receiver-operator characteristic curve analysis were applied to determine the best predictive variables and their cut-off values.

Results: ARIC score was the most significant variable in predicting pregnancy, followed by the percentage of induced acrosome-reacted sperm, serum estradiol levels on the day of hCG and sperm morphology by strict criteria. Higher spontaneous acrosome reaction had a negative relationship with pregnancy. ARIC score of 10% had a sensitivity of 85.3% and a specificity of 85.5%. The positive and negative predictive values were 64.2 and 96.6% respectively and the false positive and negative rates were 14.7 and 14.5% respectively.

Conclusion: ARIC score was a better predictor of pregnancy than conventional sperm parameters and sperm velocities.