Impact of prepubertal bovine ovarian tissue pre-freeze holding duration on follicle quality

Abstract

Ovarian tissue cryopreservation prior to gonadotoxic treatment is the only recommended option for fertility preservation in prepubertal girls. Due to the technical complexity of this technique, limited number of centres across the world are equipped to offer the facility. Hence, the retrieved ovarian tissue needs to be maintained at hypothermic temperature (4 °C) for long time during shipment. The time taken between tissue retrieval and cryopreservation could influence the functionality of cells during fertility restoration. This study explored the tissue integrity and follicle quality of ovarian cortical slices subjected to pre-freeze holding for various time durations in vitro. Prepubertal bovine ovarian tissue from < 12 months old animals were handled at hypothermic holding (4 °C) for 0, 24, 48 and 72 h. The tissues were assessed for follicle viability through confocal analysis of live-dead labelled samples, and follicle quality and tissue integrity through histology. Results have shown that follicle viability, and overall follicle quality were not significantly affected at the end of 72 h hypothermic holding. Though, the observation reassures extended hypothermic holding prior to freezing, findings need to be validated in human tissue prior to use in clinical fertility preservation programs.

Keywords: fertility preservation; follicle quality; hypothermic holding; ovarian tissue cryopreservation.