Effect of Ionomycin as an Artificial Oocyte Activator on Fertilization Outcome by ICSI

To increase the likelihood of fertilization in cases of failed oocytes activation after Intracytoplasmic sperm injection (ICSI) due to oocyte lack of activation، artificially activating oocyte is recommended. Artificial oocyte activation methods include: electrical and chemical activation. The aim of this study was to evaluate the efficiency of Ionomycin as a chemical substance that artificially activates oocyte on fertilization،cleavage rate and embryonic development، and pregnancy rates after ICSI was performed. This interventional study was held on 87 couples with male factor etiology referring to Fertility and Infertility center for treatment in 2004-2005. Semen sample was collected from participants for ICSI treatment. Routine semen analysis includingexamination of the concentration، motility and morphology، according to World Health Organization criteria، was carried out on part of it. The remaining samples were washed with Pure Sperm method and used to perform ICSI. After oocyte collection، the oocytes were randomly divided into two groups: control and artificial oocyte activation (AOA). The AOA group was chemically activated by exposure to 10μM Ionomycin for 10 minutes. Around 16-18 hours after ICSI، fertilization was assessed by presence of pronuclei. The rate of cleavage and quality of embryo were evaluated and recorded 48 and 72 hours after ICSI. Collected data were analyzed by using statistical software SPSS version 11. 5. In order to compare the mean of data between two groups T-test was held. P value less than 0. 05 was considered statistically significant. Two group (AOA and control) hadsignificant differences between mean of fertilization and cleavage rates (P<0. 001) 72 hours after ICSI. Also in patients who had no fertilization in their control group of AOA group two pregnancies were recorded. In the group whose participants had poor fertilization rate (1-3%)، the mean fertilization rate in the treatment group (58. 31%) was significantly increased than the control group (14. 3%). Artificial the oocyte activation using Ionomycin not only improves fertilization but also has positive effect on cleavage rates and embryo quality which in turn affect the implantation and pregnancy rate.