THE EFFECT OF CALCIUM IONOPHORE IN ICSI CYCLES APPLIED TO PATIENTS WITH LOW OVARIAN RESERVE

Abstract

Objectives

Several chemical, mechanical, or physical stimuli can be used to promote oocyte activation during ICSI cycles. Calcium ionophore is the most commun method for chemical oocyte activation and activation may be beneficial for cases of globozoospermia, low oocyte count, total fertilization failure, recurrent implantation failure (1,2). In what concern low ovarian reserve cases, a subgroup of infertile couples with relatively poor prognosis, artificial oocyte activation with calcium ionophore may improve fertilization rates, embryo number, embryo quality and pregnancy rates. This study aimed to find out whether Ca²⁺ ionophore improves fertilization, embryo development and pregnancy out comes in patients with low ovarian reserve.

Material - Method

This study is conducted at Istanbul University, Istanbul Faculty of Medicine, Department of Obstetrics and Gynecology, Reproductive Endocrinology and Infertility Unit. All IVF-ICSI cycles performed because of female factor, low ovarian reserve between November 2023 and July 2024 are included.Patients with DOR indication, who were administered calcium ionophore(GROUP I/Experimental Group, n:30) and patients who were not administered calcium ionophore (GROUP II/Control Group, n:30) were included. These patients were compared in terms of fertilization, embryo quality and pregnancy rates.Oocytes at the MII stage obtained from patients were subjected to ICSI approximately 4 hours after oocyte retrieval(OPU). After ICSI, the oocytes were incubated in a calcium ionophore solution for 20 minutes and then transferred to culture media. On the following days, fertilization rates, embryo development, and pregnancy statuses were assessed. The results were statistically evaluated using independent samples t-test and chi-square test. Statistical significance was considered as p<0.05

Results

No differences were observed between the two groups in terms of female age, BMI, duration of infertility, AMH, FSH, LH, estradiol, oocyte count, oocyte maturation, and fertilization rate factors.However, the transfer of medium-quality embryos was found to be significantly higher in the DOR group without calcium ionophore application(p=0.035).The number of embryos frozen in Group I was significantly higher compared to Group II (p=0.020) (Table).No significant difference was found between the two groups in terms of clinical pregnancy and ongoing pregnancy rates.

Conclusion

Alternative laboratory treatments applied to patients with low ovarian reserve may yield positive results in terms of increasing the likelihood of success. Our study has shown that the application of calcium ionophore in these cases leads to better-quality embryo development and consequently an increased number of frozen embryos. Although no significant difference was observed in clinical pregnancy and ongoing pregnancy rates, increasing the number of patients in the study could yield more definitive results.