Trial Information

Longitudinal Evaluation of Vitrification of Human Oocytes

Cryopreservation (freezing) of human gametes (unfertilized egg) provides a great potential
to preserve or extend fertility in the face of disease and social circumstances (cancer
diagnosis, delaying childbirth, single women, etc.). There are two methods for storage of
oocytes (unfertilized eggs): slow freezing or vitrification (uses higher concentrations of
cryoprotectant and faster cooling rates). Slow freezing is the standard method and has been
successful for embryos since 1983 and more recently for oocytes. Recent reports indicate
that vitrification may be more successful than slow freezing. The aim of this study is to
examine the rate at which frozen eggs survive freezing and thawing, the rate at which the
frozen/thawed eggs fertilize with sperm and the pregnancy outcomes of oocyte (egg)
vitrification cycles to determine whether the outcomes are similar or better than standard
oocyte (egg) cryopreservation (freezing) cycles.