Sperm preparation before freezing improves sperm motility and reduces apoptosis in post-freezing-thawing sperm compared with post-thawing sperm preparation

Abstract

Purpose: To evaluate whether sperm preparation (swim-up technique) before freezing improves the percentages of sperm motility, sperm viability, and non-apoptotic spermatozoa after freezing-thawing process compared with preparation after cryopreservation. Methods: Semen samples from 65 infertile males were equally divided into two aliquots one of which was processed for swim-up prior to cryopreservation and one of which was processed following cryopreservation. Sperm count, motility, and apoptosis index were measured in each group. Result (s): The total sperm count and the total motile sperm count decreased after thawing in both the pre-preparation and non-preparation groups compared with neat semen group (P < 0.001). Moreover, the percentage of apoptotic sperm in the pre-preparation group after cryopreservation was lower than that in the non-preparation group (P < 0.05), whereas the percentage of vital sperm with progressive motility was higher than that in the pre-preparation group (P < 0.001). Conclusion (s): Semen preparation by swim-up before freezing resulted in better sperm quality and fewer apoptotic sperm than sperm preparation after thawing. Therefore, sperm preparation before cryopreservation should be considered in routine sperm cryopreservation.