Bier Simone, Hanke Daniela, Zitzmann Michael, Kliesch Sabine, Nordhoff Verena
Department of Clinical and Surgical Andrology, Centre of Reproductive Medicine and Andrology, University Hospital of Münster, Münster, Germany.
Andrology. 2025 Mar 6. doi: 10.1111/andr.70019.
Cryopreservation of human semen is the cornerstone for preserving male fertility before gonadotoxic therapy or in cases of high variability in semen parameters. This is particular crucial in cases of severe oligoasthenoteratozoospermia (OAT), where diminished sperm counts may compromise planned intracytoplasmic sperm injection (ICSI) procedures. Previous investigations in donor programs have shown long-term storage effects, such as decreased motility in cryopreserved semen samples. However, these studies were based on patients exhibiting normozoospermic semen samples. To date, there has been no comprehensive evaluation of the effect of long-term cryostorage on sperm samples from individuals with compromised semen parameters.
The aim of this study was to identify the effect of long-term cryostorage on semen parameters such as motility and vitality. Additionally, we sought to identify variables, which could aid in predicting motility and vitality following the freeze-thaw process.
Within our center, we have archived sperm samples from 6022 patients cryopreserved between 2001 and 2019. Among these, 293 patients donated their samples for subsequent research following depot termination. We examined semen concentration, motility, morphology, and vitality of spermatozoa thawed after varying storage durations, alongside baseline metrics documented at the time of cryopreservation. Samples were stratified into three cohorts based on storage duration: 2.5 to ≤5 years, > 5 to ≤14 years, and > 14 years.
Our analysis revealed no changes in motility (p = 0.44), vitality (p = 0.08), or morphology (p = 0.44) across the cohorts. Regression analysis demonstrated that initial motility and sperm concentration were significantly associated with post-cryostorage motility, whereas storage duration was not (p = 0.72). Similarly, there was no association between storage duration and post-thaw value 2 vitality (p = 0.64).
The initial semen analysis as well as the evaluation of a short-term frozen sample immediately after cryopreservation, appeared to be the most important markers for predicting post-thaw motility and vitality.
Our results demonstrate the reliability of long-term cryostorage of human spermatozoa for fertility preservation, even in individuals with constrained semen quality at the time of cryopreservation.
人类精液的冷冻保存是在性腺毒性治疗前或精液参数高度可变的情况下保存男性生育能力的基石。这在严重少弱畸精子症（OAT）的情况下尤为关键，因为精子数量减少可能会影响计划中的卵胞浆内单精子注射（ICSI）程序。先前对供体项目的研究表明存在长期储存效应，例如冷冻保存的精液样本活力下降。然而，这些研究是基于精液样本正常的患者。迄今为止，尚未对长期冷冻保存对精液参数受损个体的精子样本的影响进行全面评估。
本研究的目的是确定长期冷冻保存对精液参数如活力和存活率的影响。此外，我们试图确定有助于预测冻融过程后活力和存活率的变量。
在我们中心，我们存档了2001年至2019年间冷冻保存的6022例患者的精子样本。其中，293例患者在储存期结束后捐赠样本用于后续研究。我们检查了不同储存时间后解冻的精子的精液浓度、活力、形态和存活率，以及冷冻保存时记录的基线指标。样本根据储存时间分为三个队列：2.5至≤5年、>5至≤14年和>14年。
我们的分析显示，各队列之间的活力（p = 0.44）、存活率（p = 0.08）或形态（p = 0.44）没有变化。回归分析表明，初始活力和精子浓度与冷冻保存后的活力显著相关，而储存时间则不然（p = 0.72）。同样，储存时间与解冻后存活率2之间也没有关联（p = 0.64）。
初始精液分析以及冷冻保存后立即对短期冷冻样本的评估，似乎是预测解冻后活力和存活率的最重要指标。
我们的结果表明，即使对于冷冻保存时精液质量受限的个体，人类精子的长期冷冻保存对于生育力保存也是可靠的。
