Received November 25, 2007
Accepted April 05, 2009

For many reasons women, specially in developed countries, wish to delay the age at which they become pregnant. Since the very first pregnancy was achieved in humans from previously frozen oocytes, the slow cooling method has been applied with varying success. Recent advances in oocyte and embryo cryopreservation have been reported by use of vitrification, which was originally applied in embryology by Rall & Fahy, 1985 to mouse embryos. Several methods have been devised in which very small volumes of sample to be vitrified are used.A variety of these techniques can be found in the literature and have been applied with varying degrees of success in several species of mammals, including humans. The latest approach to minimum volume vitrification is the Cryotop® device that was designed by M. Kuwayama. In our current study, we have applied the Cryotop method for vitrification from a oocyte-donation donation program, assessing development of vitrified embryos. There is one on-going pregnancy.