Variability of morphological parameters as a criterion to forecast efficiency of cryopreserved human oocytes.

Abstract

Background. Cryopreservation of oocytes becomes increasingly important in the programs of assisted reproductive technologies, as it avoids the ethical and legal problems associated with the cryopreservation of embryos. Objective. The purpose of the work was to study the morphological parameters of the oocytes and their impact on the effectiveness of cryopreservation. Methods. This is a retrospective data analysis of IVF cycles using vitrified oocytes. The 724 mature oocytes with dysmorphism and normal morphology were vitrified using CryoTec by vitrification method. A total of 724 mature oocytes were vitrified. P-level critical value was 0,05. Results It was shown that evaluation and selection of the most promising cell material prior to freezing can be carried out using the qualitative morphological criteria, as there has been revealed the relationship between these criteria and the success of cryopreservation. Qualitative parameters to select the cryoresistant oocytes are as follows: state of the first polar body, Zona pellucida and cytoplasm. The results showed that classification based on oocytes morphology revealed a significant correlation with survival after cryopreservation, fertilization rate and in vitro development of embryos to blastocyst stage. Conclusion. The proposed criteria for assessing the morphofunctional state of oocytes prior to cryopreservation contribute to the effectiveness of the treatment of infertility by means of in vitro fertilization.