Comparison between two different cryoprotectants for human sperm, with emphasis on survival

Abstract: The increasing number of patients undergoing treatment with assisted reproductive techniques (ART) during the past years have led to the need of developing different methods for separation of spermatozoa that can be used for different fertilisation procedures and for freezing. Cryopreservation of spermatozoa includes preparation, freezing, storage and thawing. In this study two different cryomedia (Cryo Protec I and Cryo Protec II) for human spermatozoa were compared. The main outcome was spermsurvival rate for spermatozoa after freezing. Sperm viability was assessed using the Hypo-osmotic swelling test which is based on osmolality. A total of 86 samples of semen were used in this study (Cryo Protec I=38, Cryo Protec II=48). The survival rate between the two cryomedia did not differ much but Cryo Protectant I showed a small increase in survival for the spermatozoa after freezing. The Hypo-osmotic swelling test also showed similar values of viable spermatozoa for the two cryomedia both before and after freezing.