Cryopreservation of human spermatozoa: Comparison of TEST-yolk buffer and glycerol

Objective-Comparison of human sperm motility, morphology, and sperm membran e integrity using two cryoprotective media, Test-yolk buffer with glycerol and glycerol alone. Methods-Semen samples from 10 healthy donors were divid ed and frozen with either glycerol or a combination of glycerol and TEST-yo lk buffer. Semen characteristics were evaluated before freezing and after t hawing. Motility was measured at 0, 60, 120, and 180 minutes post-thaw foll owing removal of the cryoprotectant (post-wash). Results-Percentage of moti le sperm decreased significantly compared to prefreeze values in both group s. Post-thaw motility following removal of the freezing media was higher in specimens that were frozen in TEST-yolk buffer compared to these frozen in glycerol at 0 minutes (P = 0.004). Similarly, specimens cryopreserved in T EST-yolk buffer had higher sperm motility compared to aliquots that were fr ozen in glycerol at 180 minutes (P = 0.013). The percentage of normal sperm forms was significantly higher post-wash and postthaw in specimens that we re cryopreserved in TEST-yolk buffer (P = 0.04). Conclusions-Sperm cryopres erved in TEST-yolk buffer had significantly better motility, morphology, an d sperm membrane integrity than sperm preserved in glycerol alone.