Human oocyte vitrification with corona radiata, in autologous follicular fluid supplemented with ethylene glycol, preserves conventional IVF potential: birth of four healthy babies.

The aim of this study was to examine the effects of vitrification with autologous follicular fluid (AFF) supplemented with ethylene glycol (EG) and sucrose on human oocytes with corona radiata. A total of 182 human oocytes with corona radiata from fifteen infertile patients were vitrified using either equilibration solutions (ES) and vitrification solution (VS) consisting of AFF, EG and sucrose (AFF group, n=67) or commercial ES and VS (control group, n=115). All oocytes were thawed in the next cycle, with surviving oocytes being inseminated by conventional IVF. The clinical outcome of vitrified-warmed oocytes by both vitrification methods was analysed retrospectively. In the AFF group, six patients received embryo transfer, with three couples taking four healthy babies home. In the control group, nine patients received embryo transfer, with four couples taking five healthy babies home. There was no significant difference in the survival rate (91.0 vs 92.2%), two pronuclei (2PN) fertilisation rate (73.8 vs 73.6%), cleavage rate (100 vs 100%), top-quality embryo rate (62.2 vs 59.2%), clinical pregnancy rate (50.0 vs 44.4%), implantation rate (33.3 vs 25%) or take-home baby rate (50.0 vs 44.4%) between the AFF group and the control group, respectively. These results show that AFF supplemented with EG and sucrose is an efficient, cost-effective cryoprotectant for human oocyte cryopreservation. A corona radiata on vitrified-warmed oocytes retains the oocytes' fertilisation capability in conventional IVF.