Vitrfication and Slow Freezing for Cryopreservation of Germinal Vesicle-Stage Human Oocytes: A Bayesian Meta-Analysis.

BACKGROUND

T he most commonly used methods for the cryopreservation of oocytes and embryos are vitrification and slow freezing.

OBJECTIVE

The aim of this study was to to investigate whether there are differences in survival, in vitro maturation (IVM), and fertilization rates between cryopreserved immature oocytes, especially germinal vesicle (GV)-stage human oocytes, following vitrification and slow freezing.

MATERIALS AND METHODS

A literature search was performed using the MEDLINE, Cochrane Central Register of Controlled Trials, and Embase databases. A total of three studies were included in the Bayesian meta-analysis.

RESULTS

There was no difference in survival rates between vitrification and slow freezing. Additionally, there was no difference in IVM rates and fertilization rates between vitrification and slow freezing.

CONCLUSION

The superiority of vitrification over slow freezing for cryopreservation of GV-stage human oocytes remains unclear. Additional studies on cytoarchitecture and modification of the cryopreservation protocol are essential to achieve strong conclusions.