Oocyte Cryopreservation: Slow Cooling Versus Vitrification Techniques on Oocyte Survival

Oocyte cryopreservation has been studied for many years without much success in refining a method that has consistent, reliable results in producing viable embryos and clinical pregnancies. In 1986 the first baby was born from an embryo created from a frozen oocyte; however, since then there have been less than 150 births from frozen eggs. To date, there are no reportable adverse outcomes in the children born from frozen oocytes. The research continues to look at different methods of oocyte cryopreservation. Many smaller studies have been conducted with some success but larger clinical trials are needed to replicate these findings. The conventional cryopreservation technique has been slow cooling with differing methods of freezing; however, vitrification is now being researched as the potential cryopreserving method that holds some promise for the future. Our hypothesis is the use of vitrification (quick freezing) to cryopreserve oocytes in patients undergoing in-vitro fertilization will be more successful than slow freezing in oocyte survival, fertilization rate with ICSI and subsequent embryo development, implantation rate and pregnancy rate.