A Study on the Sperm Motility According to the Cryopreservation method of Human Semen

Chang, Soo Kee; Lee, Moo Sang

Abstract

There is a general growing appreciation that clinical use of frozen-stored human semen is a practical, successful, safe and valuable method in both infertility and population control. However cryopreservation results in reduced motility and fertility of human semen. The factors which influence cryosurvival of human semen are poorly understood. The influence of initial temperature of cryopreservation, ratios of HSPM to semen, cooling rates, freezing rates, thawing methods and duration of cryopreservation on the survival of human spermatozoa was studied. The following results were obtained by carefully observing the motility of post-thaw sperms. 1. Ratios of 1:1, 1:2, 1:3, and 1:4 of HSPM to semen did not affect sperm cryosurvival. 2. The initial temperature of cryopreservation had no significant influence on the cryosurvival of spermatozoa. 3. The optimal cooling rate from room temperature(20+/-2 degrees C) to 4 degrees C and subsequently frozen-thawed in LN2 was found to be 0.5C and 1 degrees C per minute. 4. The optimal freezing rate from 4 degrees C to -80 degrees C was found to be 5 degrees C and 10 degrees C per minute. 5. Slow thawing in room temperature(20+/-2 degrees C) resulted in better survival than rapid thawing in 37 degrees C. 6. There was no significant difference in the post-thaw sperm motility up to 5 months cryopreservation.