Increased sperm motility after in-vitro culture of testicular biopsies from obstructive azoospermic patients results in better post-thaw recovery rate

The objective of this study was to optimize the use of testicular biopsies in 14 patients with obstructive azoospermia. Testicular specimens were retrieved from six patients (group I) and cultured at 32 and 37°C for up to 20 days; changes in percentage motile spermatozoa were compared. In four men of group I, one portion of the specimen was frozen at retrieval, and changes in post-thaw motility after 24 h of culture at 37°C were recorded. In the other eight patients (group II), testicular specimens were frozen at retrieval and after 72 h culture at 37°C. Pre- and post-freezing motility and post-thaw recovery rate were compared. No significant differences were observed until day 8 in the improvement of motility between 32 and 37°C in-vitro culture. Maximum motility was reached, under both conditions, between 48 h and 72 h. Post-thaw 24 h culture at 37°C of specimens frozen at retrieval did not improve motility; however, 72 h pre-freezing culture significantly improved initial motility (P < 0.01), post-thaw motility (P < 0.01) and post-thaw recovery rate (P < 0.001). The higher recovery rate of samples frozen 3 days after retrieval allows more economical use of the tissue that is available.