Abstract: Objective：To assess the application of a variety of cryopreservation carriers in the cryopreservation of rare human sperm. Methods: We searched the Pubmed, ScienceDirect, SpringerLink, Willey Online Library, CNKI, VIP, WanFang databases for those relevant studies on the cryopreservation of rare human sperm up to December of 2016. The quality of the included studies was assessed according to Newcastle-Ottawa Scale(NOS). A standardized data extraction sheet was developed. Results: Identified total of 31 non-random experimental studies were identified, including 13 cryopreservation carriers used for rare human sperm. The recovery rate of sperm varied widely from 59% to 100%, and the average survival rate was 73.7%. The frozen-thawed sperm was subsequently used clinically via intracytoplasmic sperm injection (ICSI) in nine studies, and the fertilization rates were in the range of 18%~71%. Embryo transfer (ET) was performed in five studies, and 3 cases of healthy live births was reported. Conclusions: To date, there is not an ideal cryopreservationcarrier for rare human sperm in clinical practice. It is necessary to have the controlled multicenter trial to evaluate furtherly the effectiveness of those cryopreservation carriers.

Key words: Spermatozoa, Freezing, Cryopreservation, Sperm injections, intracytoplasmic, Cryopreservation carrier