INTRACYTOPLASMIC SPERM INJECTION USING IMMOBILIZED OR MOTILE HUMAN SPERMATOZOON

Objectives: To investigate the efficacy of the treatments for oocyte activation on the results of intracytoplasmic sperm injection using immobilized or motile human spermatozoa. Design: The protocol of intracytoplasmic sperm injection was divided into four groups according to the states of sperm used for microinjection and the treatment for oocyte activation. In group A, immobilized sperm is used. The oocyte is activated merely by aspiration of the cytoplasm into the pipette. In group B, immobilized sperm is used. Microinjected oocyte is treated with A23187. In group C, immobilized sperm is used. Electroporation is performed on the microinjected oocyte. In group D, motile sperm is used. The oocyte is activated merely by aspiration of the cytoplasm into the pipette. Setting: The Obstetrics and Gynecology Hospital, Fukushima Medical College. Patients: The subjects are the cases that had failed fertilization in standard IVF, cases of severe oligozoospermia, and cases of severe asthenozoospermia. Results: No difference was found between the groups as to the survival rate and fertilizing rates of oocytes after intracytoplasmic sperm injection. The cleavage rate of oocytes was high in order of group D, C, B, A. The cleavage rate for groups D, C, and B was significantly higher than group A. Cases of pregnancy were found in groups D and B. Conclusion: Using motile sperm rather than immobilized sperm can be expected to produce better results in human ICSI. Activating oocytes positively is needed when immobilized sperm is used.