Effect of oocyte activation with calcium ionophore on ICSI outcomes in teratospermia: A randomized clinical trial

BACKGROUND Chemical activation is the most frequently used method for artificial oocyte activation (AOA), results in high fertilization rate. OBJECTIVE This prospective, randomized, unblinded, clinical study aimed to evaluate the efficiency of oocyte activation with calcium ionophore on fertilization and pregnancy rate after intracytoplasmic sperm injection (ICSI) in infertile men suffer from teratoospermia. MATERIALS AND METHODS Thirty eight women with teratoospermic partner underwent ICSI with antagonist protocol. A total of 313 metaphase II (MII) oocytes were randomly divided into two groups: In the oocytes of the control group (n=145), routine ICSI was applied. Oocytes in the AOA group (n=168) immediately after ICSI, were entered in culture medium supplemented with 5 µΜ calcium ionophore (A23187) for 5 minutes and then washed at least five times with MOPS solution. In both groups, the fertilization was evaluated 16-18 hours after ICSI. RESULTS The number of fertilized oocytes and embryos obtained were significantly different between two groups (p=0.04). There was no significant difference between the two studied groups regarding the fertilization and cleavage rate (95.33% vs. 84.4%, p=0.11; and 89.56% vs. 87.74%, p=0.76, respectively). Implantation rate was higher in AOA group than in control group, but the difference was not significant (17.64% vs. 7.4%, p=0.14). No significant differences were observed in chemical and clinical pregnancy rate between groups (47.1% vs. 16.7%, p=0.07; and 41.2% vs. 16.7%; p=0.14, respectively). CONCLUSION We didn't find significant difference in the implantation, fertilization, cleavage and pregnancy rates between the two groups but could significantly increase the number of fertilized oocytes and embryos obtained. Finally oocyte activation with calcium ionophore may improve ICSI outcomes in infertile men suffer from teratoospermia. Further study with more cases can provide greater value.