Clinically applied procedures for human ovarian ti

Authors: Lobke Bastings Johan R Westphal Catharina C M Beerendonk Ruud L M Bekkers Petra L M Zusterzeel Jan C M Hendriks Didi D M Braat Ronald Peek

Publish Date: 2016/10/06

Volume: 33, Issue: 12, Pages: 1605-1614

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Abstract

Different protocols are being used worldwide for the cryopreservation of human ovarian tissue for fertility preservation purposes The efficiency and efficacy of the majority of these protocols has not been extensively evaluated possibly resulting in suboptimally cryopreserved ovarian tissue To address the impact of this issue we assessed the effects of two clinically successful human ovarian tissue slowfreezing cryopreservation procedures on the quality of the cryopreserved tissueTo differentiate between cryopreservation C versus thawing T related effects four combinations of these two A and B very different cryopreservation/thawing protocols ACAT ACBT BCAT BCBT were studied Before and after cryopreservation and thawing the percentage of living and morphologically normal follicles as well as the overall tissue viability was assessedOur experiments revealed that the choice of the cryopreservation protocol noticeably affected the overall tissue viability and percentage of living follicles with a higher viability after protocol BC when compared to AC No statistically significant differences in tissue viability were observed between the two thawing protocols but thawing protocol BT required considerably more human effort and materials than thawing protocol AT Tissue morphology was best retained using the BCAT combinationThe survival of pediatric adolescent and young adult cancer patients has significantly improved during the past decades 1 As a consequence the attention to issues related to quality of life after cancer has increased in oncological care With many types of oncological therapy posing a threat to the ovarian function 2 techniques aimed at preserving fertility in girls and young women have emerged and evolved 3 In this paper we focus on the cryopreservation of ovarian tissue In prepubertal girls and in women who cannot delay the start of chemotherapy this is the only available option for fertility preservation 4 5 The ovarian tissue is obtained before start of the gonadotoxic anticancer therapy and can be autotransplanted to the patient after she has been cured of her disease to restore her fertility In three major European centers for fertility preservation a pregnancy rate of 27  was reported after autotransplantation of ovarian tissue and more than 60 babies have been born worldwide 5 6 7The freezing/thawing protocol used for cryopreservation of the ovarian tissue is most likely to be an important factor in determining the clinical outcome ie live birth of ovarian tissue autotransplantation Several laboratory procedures that have led to the birth of healthy children have been published 8 9 10 11 12 13 14 15 16 17The mere fact that children were born using a certain protocol however does not automatically imply that this protocol had been optimized to its maximum potential In other words tweaking the protocol might have led to an even higher success rate To address this matter we compared the impact of two clinically successful but methodologically very different freezing and thawing laboratory procedures on the quality of the cryopreserved tissue To determine the contribution of the freezing and the thawing procedure on the human ovarian tissue quality we analyzed the effects of these events separately

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