A study on the changes of sperm motility according to freezing and thawing methods

Ju, Yong Tak; Park, Hye Won; Yoon, Eun Suk; Ku, Chun Hoe; Kim, Seok Yong; Son, Dong Woo; Lee, Byung Seok; Lee, Ji Sung

Abstract

OBJECTIVE
To figure out the more optimal method for freezing and thawing the sperm, we compared with the sperm motility after handling of the sperm based on the different types of freezing and thawing methods.
METHODS
Twenty four adult males who visited our infertility clinic from Aug 2004 to Feb 2005 were enrolled. We applied two kinds of freezing method to normal sperm according to WHO standard criteria; automatic slow freezing method (Auto) and manual vapor freezing method (Manu). We also use two different methods of thawing; a 37 degreesC warm water bath (37 degreesC) and 22 degreesC room temperature thawing (22 degreesC). Mean motile percent (MMP) was compared by the freezing methods and thawing methods respectively. We also evaluated the motility in four different ways of freezing and thawing combination. A written informed consent was obtained from each client. This study was approved by IRB.
RESULTS
MMP by the freezing method was 56% in Auto group and 52% in Manu group. It was significantly different (P=0.037). In thawing method, it was 59% in 37 degreesC group and 49% in 22 degreesC group (P=0.000). Each of freezing and thawing methods was joined to make four different types of freezing and thawing combinations. In MMP there were 63% in Auto/37 degreesC, 50% in Auto/22 degreesC, 56% in Manu/37 degreesC and 48% in Manu/22 degreesC (P>0.05).
CONCLUSION
The automatic method in freezing and room temperature in thawing showed respectively the highest MMP. In four different types of freezing and thawing combinations, Auto/37 degreesC MMP was the highest. There was no statistical difference. This means that all four types of freezing and thawing methods might be used clinically. If further study of larger population or comparison of fertility is done, we would have a better result.