Fast and furious: successful survival and resumption of meiosis in immature human oocytes vitrified and warmed using a short protocol.

Research Question: Can immature oocytes vitrified and warmed using a short protocol survive and resume meiosis?

Design: This study examined modifications of oocyte vitrification and warming protocols that reduce the length of exposure to vitrification and warming solutions. In total, 561 germinal vesicles and 218 metaphase I oocytes that were immature at oocyte retrieval were vitrified at room temperature for 2 min. Warming was performed at 37°C for 2 min.

Fast and furious: pregnancy outcome with one-step rehydration in the warming protocol for human blastocysts.

Research Question: Do embryos warmed using a one-step rehydration protocol with a more efficient workflow result in comparable pregnancy rates to the standard multi-step rehydration protocol?

Design: A retrospective cohort study of 3439 frozen embryo transfers (FET). Clinical outcomes of 833 FETs using a one-step rehydration protocol were reviewed and compared with results from the control group (2606 FETs using standard multi-step rehydration protocol). Primary outcome was ongoing pregnancy rate.

Vitrification demonstrates significant improvement versus slow freezing of human blastocysts.

Blastocyst culture has reduced the number of embryos transferred per cycle, whilst simultaneously creating new quandaries regarding supernumerary blastocyst cryopreservation. This retrospective study was undertaken to compare a slow freezing protocol to a vitrification protocol for cryopreservation of day 5 and day 6 human blastocysts. To demonstrate this, the survival, implantation rate and pregnancy rates were compared after thawing, assessment and embryo transfer of 86 consecutive day 5 and day 6 thawed blastocyst transfer cycles from January 1, 2002 to December 31, 2003.