%0 Journal Article
%T Evaluation of Serial Thawing-Refreezing on Human Spermatozoa Resistance Using Cryovials and Straws
%A Fatemeh Ghasemian
%A Roya Faraji
%A Mohaddese Mohammadi Sardoo
%A Mohammad Hadi Bahadori
%J International Journal of Fertility & Sterility
%D 2012
%I Royan Institute
%X Background: We designed this study to detect the cryoinjury rate on human sperm after serialfreezing and thawing, taking into consideration the effects of using cryovials and straws.Materials and Methods: In this experimental study, semen specimens obtained from 15 subjectswere divided into normozoospermic and oligozoospermic groups. Each of the normozoospermicand oligozoo spermic semen specimens were additionally divided into two groups: i. washed andii. unwashed. Specimens were repeatedly freeze-thawed by using cryovials and straws with thefast liquid nitrogen vapor method, until no motile sperm remained. Sperm motility, recovery, andmorphology rate were then determined after thawing, and compared between the groups whiletaking into consideration the effects of using cryovials and straws.Results: Motile spermatozoa were observed in all normozoospermic samples up to thaw 6 with bothcryovials and straws while in oligozoospermic specimens up to thaw 4 (straw) and thaw 3 (cryovial)in the freeze-thawing cycle. Normozoospermic sample analysis showed no significant difference inmorphology rate. There was a significant increase in motility and recovery percentages for washedsamples, which was observed with straws in compared to the unwashed groups. Oligozoospermicsample analysis indicated a significant increase in motility, recovery (p<0.01), and morphology(p<0.001) rates in washed specimens compared to unwashed specimens using straws. Theimportance of washing sperm was obvious for oligozoospermic specimens.Conclusion: Normozoospermic sperm resisted freezing longer than oligozoospermic sperm. Use ofstraws and cryovials made significant differences in motility, recovery, and morphology of sperm ineach thaw. This difference was slightly higher for oligozoospermic specimens. Results indicated thatthe percentage of motility was higher for washed normozoospermic specimens in each thaw whenstraws were used, whereas the percentage of motility, recovery, and morphology were promotedafter frozen oligozoospermic specimens were washed using straws.
%K Semen
%K Oligozoospermia
%K Freezing - Thawing
%U http://www.ijfs.ir/library/upload/article/af_46483443833344522425433426447432223323343.pdf