Cryopreservation of Oocytes : Comparison between the Cryoloop and the Cryopette vitrification techniques

Sammanfattning: Crypreservation of oocytes is recently being considered to be a valid choice in infertility treatments.Low survival and fertilization rates due to inefficient slow freeze protocols have been the outcome ofmany previous studies done in the field. However, introduction of the vitrification technique and itsapplication in reproductive medicine and to some extent new improved slow freeze protocols haveshown that oocytes can be cryopreserved with successful outcome. In this project the survival rate of oocytes after vitrification with MediCult Vitrification andWarming Media has been studied. Also, a comparison of the carriers Cryoloop (an open system) andCryopette (a closed system) has been performed. A total of 43 oocytes were vitrified and warmed according to MediCult's protocol, of which 21oocytes with Cryoloop and 22 with Cryopette. The cells were post-thaw incubated in a physiologicalenvironment for 24h. During that time the morphology and viability were observed and noted after 2h,over night and after 24h. No significant difference in survival rates of the oocytes' was observed usingthe two carriers, and the total survival rate of the oocytes was 83.7%. This indicates thatcryopreservation of oocytes is a valid choice in fertility treatments and that the new product Cryopettecan be used clinically with just as good results as the well established Cryoloop technique. This merits further studies on the applicability of vitrification on oocytes and the Cryopette technique.