Reduced motility longevity in thawed human spermatozoa.

Fifty ejaculates from donors serving on an AID panel were divided into two 0.5 aliquots and evaluated for initial motility and kinetics. The first aliquot was then diluted with Tyrode solution and incubated in a Tyrode atmosphere at 37 degrees C. Motility and kinetics were evaluated at 1, 3, 6, and 9 hr. The second aliquot was frozen and thawed 24 hr later. The aliquot was then diluted with Tyrode solution, incubated, and evaluated as before. The results indicate a significant reduction in motility longevity of the thawed aliquots. A significant reduction in kinetics of the thawed aliquots was also discovered. These findings suggest that decreased motility longevity of thawed semen may offer an explanation for reduced pregnancy rates using cryopreserved semen.