Aseptische Vitrifikation in die Praxis umsetzen

Vitrification is a cryopreservation strategy where cells are converted into a glass-like amorphous solid, which is free of any crystalline structure. Such process is achieved by a combination of high concentrations of cryoprotectant and an extremely high cooling rate. In the last years, survival rates of up to 80 % after thawing and pregnancy rates of almost 30 % could be achieved after transfer of vitrified embryos at the zygote, cleavage, morula and blastocyst stages. Also deliveries of healthy babies have been reported numerous times. To this day, a limited interest in this technique can be noted. The explanation may lie in the apprehension of many ART units regarding exposure of embryos to high concentrations of
cryoprotectants and storage in non sterile conditions.
The aim of the first part of the article is to analyse if such fears are justified due to the fact, that slow-cooling and storage of embryos based upon high aseptic conditions is presently possible. In the second part, results on survival after thawing, pregnancy-rates and baby-take-home-rates of vitrified embryos will be presented and the problems associated with vitrification of blastocysts will be discussed. J Reproduktionsmed Endokrinol 2008; 5 (3): 121–31.