Spermac stain analysis of human sperm acrosomes

Objective: To study the association between low percentages of intact sperm acrosomes and fertilization failures in conventional IVF procedures. Design: A retrospective study. Setting: Clinical and academic research environment. Patient(s): Patients undergoing treatment of infertility. Intervention(s): Sperm cells were fixed and stained using the Spermac stain. Main Outcome Measure(s): Percentages of intact acrosomes and fertilization. Result(s): There was a significant association between specimens with <40% intact acrosomes and failed conventional IVF procedures. Among the 29 cases with <40% intact acrosomes, 9 cases (31%) resulted in zero penetration of the oocytes. The mean (±SEM) percentage of fertilization was lower in the abnormal acrosome group (43.3% ± 6.5%) than in the normal acrosome group (64.1% ± 5.6%). The status of the sperm acrosome was not correlated with the results of fertilization in intracytoplasmic sperm injection procedures. Conclusion(s): Sperm with low percentages of intact acrosomes were associated with failed fertilization. The Spermac stain was useful for assessing acrosomes and identifying possible male factor infertility problems. The results suggested that a minimum percentage of sperm with intact acrosomes are needed for fertilization to occur in vitro.