Semen analysis data from fresh and cryopreserved donor ejaculates: Comparison of cryoprotectants and pregnancy rates

Patients (155) were selected at random for fresh or cryopreserved semen and inseminated on the predicted day of ovulation. Semen analysis was performed using a microcomputerized multiple-exposure photography system. Frozen semen was used with either glycerol or TEST-yolk (TEST-buffered 20% egg yolk with 10% glycerol) as the cryoprotectant. Cryopreservation resulted in significant decreases in all semen parameters measured. Of these, velocity appeared to be the least effected. TEST-yolk provided significantly more protection against a reduction in velocity compared with glycerol. A total of 18, 17, and 27 patients conceived using fresh, glycerol, or TEST-yolk-preserved semen, repectively. For these same groups, a cumulative pregnancy rate of 52.9%, 27.1%, and 68.5%, respectively, was observed (not significant). The total number of motile sperm per insemination used for fresh artificial inseminations resulting in conception (132.4 x 10⁶) was significantly greater than the number used for successful glycerol- and TEST-yolk-preserved serum (approximately 24 x 10⁶). These results demonstrate that although the number of motile sperm of cryopreserved ejaculates are dramatically reduced compared with the fresh counterparts, if a mimimum criteria for ejaculate quality is established, the use of cryopreserved semen can offer a viable, effective, and relatively safe alternative to artificial insemination by donor with fresh semen.