Objective: To determine whether intracytoplasmic sperm injection has an adverse effect on the meiotic spindle of oocytes after injection of a sperm into the ooplasm.
Design: Hamster oocytes were injected with human sperm (Test group) and evaluated for meiotic spindle and chromosome morphology using immunofluorescent staining. Results were compared with control uninjected oocytes exposed to the microscope environment (CS group) and untreated oocytes remaining in the incubator (CI group).
Setting: Basic research center at a medical school.
Results: No significant differences were noted in spindle appearance and chromosome alignment between Test (13 abnormal/68 normal) and both control groups (CS 9/73 and CI 12/71; P = 0.602).
Conclusion: Our results demonstrate that injection of human sperm into the cytoplasm of hamster oocytes may not result in a significant increase in damage to the meiotic spindle provided care is taken to orient the polar body away from the site of injection.