IMPROVED RESULTS OF THAWED SPERM CRYOPRESERVED WITH SLOW STAGE - COOLING WITH A CELLEVATOR

There is a need to develop a sperm cryopreservation technique that wil l allow good pregnancy rates following intrauterine insemination of th awed semen specimens that have been frozen prior to sperm-destructive procedures, such as surgery, chemotherapy, or radiation therapy. A slo wer cooling rate using a commercial semiprogrammable freezer may provi de improved post-thaw motility and hypoosmotic swelling (HOS) test sco res. However, the cost of this apparatus precludes it from being used in most andrology centers. This study compares the efficacy of slow st age cooling using an inexpensive cellevator (a device used to freeze l ymphocytes) to liquid nitrogen vapor freezing. The semen from 27 males was equally divided and one aliquot was cryopreserved with the cellev ator stage cooling and the other with the liquid nitrogen vapor techni que. The percent motility and percent grade A sperm post-thaw were sig nificantly higher when cryopreserved with the cellevator than with vap or freezing, as was the mean percentage of sperm showing HOS changes.