Pilot surveys for proficiency testing of semen analysis. Comparison of dry-ice vs liquid nitrogen shipments

Two pilot surveys involving routine semen analysis were provided to eight and nine selected laboratories. The laboratories were selected for expertise and geographic diversity. Manual and computer-assisted semen analysis were performed by the participating laboratories on pooled cryopreserved human semen samples following shipment either on dry-ice pellets or in liquid nitrogen (dry shippers). Coefficient of variation values obtained were 13% to 39% for concentration, 19% to 127% for motility, and 42% to 90% for viability. Motility was impaired for sperm shipped on dry ice. However, variances and performance criteria can be established for all analyses. A semen analysis survey is feasible but expensive owing to the shipping costs of cryopreserved semen.