STUDY QUESTION What are the reproductive outcomes of patients who cryopreserved oocytes or embryos in the context of fertility preservation in the Netherlands? SUMMARY ANSWER This study shows that after a 10-year follow-up period, the utilization rate to attempt pregnancy using cryopreserved oocytes or embryos was 25.5% and the cumulative live birth rate after embryo transfer was 34.6% per patient. WHAT IS KNOWN ALREADY Fertility preservation by freezing oocytes or embryos is an established treatment for women with a risk of premature ovarian failure (caused by a benign or oncological disease) or physiological age-related fertility decline. Little is known about the success of cryopreservation, the utilization rate of oocytes or embryos, or the live birth rates. STUDY DESIGN, SIZE, DURATION A retrospective observational study was performed in the Netherlands. Data were collected between 2017 and 2019 from 1112 women who cryopreserved oocytes or embryos more than 2 years ago in the context of fertility preservation in 10 IVF centers in the Netherlands. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 1112 women were included in this study. Medical files and patient databases were used to extract data. Women were categorized based on indication of fertility preservation: oncological, benign, or non-medical. To indicate statistical differences the t-test or Mann-Whitney U test was used. Kaplan-Meier analyses were used for time endpoints, and log-rank analyses were used to assess statistical differences. The study protocol was approved by the medical ethics committee. MAIN RESULTS AND THE ROLE OF CHANCE Fertility preservation cycles have been performed increasingly over the years in the Netherlands. In the first years, less than 10 cycles per year were performed, increasing to more than 300 cycles per year 10 years later. Initially, embryos were frozen in the context of fertility preservation. In later years, cryopreservation of oocytes became the standard approach. Cryopreservation of oocytes versus embryos resulted in comparable numbers of used embryos (median of 2) for transfer and comparable live birth rates (33.9% and 34.6%, respectively). The 5-year utilization rate was 12.3% and the 10-year utilization rate was 25.5%. The cumulative clinical pregnancy rate was 35.6% and the cumulative live birth rate was 34.6% per patient. Those who had fertility preservation due to benign diseases returned earlier to use their cryopreserved embryos or oocytes. LIMITATIONS, REASONS FOR CAUTION The follow-up period after the fertility preservation procedure varied between patients in this study and not all frozen oocytes or embryos had been used at the end of this study. This might have led to underestimated outcomes reported in this study. Furthermore, intention to treat cannot be fully determined since women who started the fertility preservation procedure without success (cancellation due to low response) were not included in this study. WIDER IMPLICATIONS OF THE FINDINGS This study provides data on the reproductive outcomes after various indications of fertility preservation. This knowledge can be informative for professionals and future patients to improve counseling and informed decision making regarding ovarian stimulation in the context of fertility preservation. STUDY FUNDING/COMPETING INTEREST(S) No funding was obtained for this study. The authors have no conflicts of interest to declare related to this study. V.T.H. received grants paid to the institute for studies outside the present work from AstraZeneca, Gilead, Novartis, Eli Lily, Pfizer, and Daiichi Sankyo. V.T.H. received consulting fees from Eli Lily outside the present work. M.G. received grants paid to the institute for studies outside the present work from Guerbet and Ferring. E.M.E.B. received a grant from The Dutch Network of Fertility Preservation for a study outside the present work. TRIAL REGISTRATION NUMBER N/A.

中文翻译：

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荷兰卵母细胞或胚胎冷冻保存女性生育能力的结果：一项基于人群的研究。


研究问题：在荷兰保留生育能力的情况下，冷冻保存卵母细胞或胚胎的患者的生殖结果如何？摘要答案 这项研究表明，经过 10 年的随访期，使用冷冻保存的卵母细胞或胚胎尝试怀孕的利用率为 25.5%，胚胎移植后每例患者的累积活产率为 34.6%。已知的 通过冷冻卵母细胞或胚胎来保存生育能力是一种既定的治疗方法，适用于有卵巢早衰风险（由良性或肿瘤疾病引起）或生理性年龄相关生育能力下降的女性。人们对冷冻保存的成功、卵母细胞或胚胎的利用率或活产率知之甚少。研究设计、规模、持续时间 在荷兰进行了一项回顾性观察研究。数据是在 2017 年至 2019 年间从荷兰 10 个 IVF 中心的 1112 名女性那里收集的，这些女性在 2 年多前在保留生育能力的背景下冷冻保存了卵母细胞或胚胎。参与者/材料、环境、方法 本研究共纳入 1112 名女性。使用医疗文件和患者数据库来提取数据。根据保留生育能力的指征对女性进行分类：肿瘤、良性或非医学。为了表示统计差异，使用了 t 检验或 Mann-Whitney U 检验。Kaplan-Meier 分析用于时间终点，对数秩分析用于评估统计差异。该研究方案得到了医学伦理委员会的批准。主要结果和机会的作用 多年来，荷兰越来越多地进行生育力保存周期。 在最初几年，每年进行的周期少于 10 个，10 年后增加到每年 300 多个周期。最初，胚胎是在保持生育能力的背景下冷冻的。在后来的几年里，卵母细胞的冷冻保存成为标准方法。卵母细胞与胚胎的冷冻保存导致用于移植的可用胚胎数量相当 （中位数为 2） 和相当的活产率 （分别为 33.9% 和 34.6%）。5 年利用率为 12.3%，10 年利用率为 25.5%。每例患者累积临床妊娠率为 35.6%，累积活产率为 34.6%。那些因良性疾病而保留生育能力的人更早地返回使用冷冻保存的胚胎或卵母细胞。局限性，谨慎的原因 在本研究中，保留生育能力程序后的随访期因患者而异，并且在本研究结束时并非所有冷冻卵母细胞或胚胎都已使用。这可能导致本研究报告的结局被低估。此外，由于开始生育力保留程序未成功 （由于反应低而取消） 的女性未被纳入本研究，因此无法完全确定治疗的意图。研究结果的更广泛意义 本研究提供了各种生育能力保留适应症后的生殖结果数据。这些知识可以为专业人士和未来的患者提供信息，以在保持生育能力的背景下改进有关卵巢刺激的咨询和明智的决策。研究资金/竞争利益 本研究没有获得资金。作者没有与本研究相关的利益冲突需要声明。V.T.H. 收到了阿斯利康、吉利德、诺华、礼合、辉瑞和第一三共支付给研究所的资助，用于当前工作之外的研究。V.T.H. 在目前的工作之外从 Eli Lily 那里收到了咨询费。M.G. 从 Guerbet 和 Ferring 那里获得了支付给研究所的资助，用于当前工作之外的研究。E.M.E.B. 获得了荷兰生育力保存网络的资助，用于本研究之外的一项研究。试验注册号 N/A。