Cryopreservation of human spermatozoa: comparison of TEST-yolk buffer and glycerol.

OBJECTIVE Comparison of human sperm motility, morphology, and sperm membrane integrity using two cryoprotective media, Test-yolk buffer with glycerol and glycerol alone. METHODS Semen samples from 10 healthy donors were divided and frozen with either glycerol or a combination of glycerol and TEST-yolk buffer. Semen characteristics were evaluated before freezing and after thawing. Motility was measured at 0, 60, 120, and 180 minutes post-thaw following removal of the cryoprotectant (post-wash). RESULTS Percentage of motile sperm decreased significantly compared to prefreeze values in both groups. Post-thaw motility following removal of the freezing media was higher in specimens that were frozen in TEST-yolk buffer compared to those frozen in glycerol at 0 minutes (P = 0.004). Similarly, specimens cryopreserved in TEST-yolk buffer had higher sperm motility compared to aliquots that were frozen in glycerol at 180 minutes (P = 0.013). The percentage of normal sperm forms was significantly higher post-wash and post-thaw in specimens that were cryopreserved in TEST-yolk buffer (P = 0.04). CONCLUSIONS Sperm cryopreserved in TEST-yolk buffer had significantly better motility, morphology, and sperm membrane integrity than sperm preserved in glycerol alone.