Experimental Ovarian Tissue Freezing Could Delay Menopause, but Experts Are Weighing the Risks

Hot flashes, insomnia and mood swings are among the difficult symptoms that affect some people experiencing menopause. While symptoms are typically temporary and treatable, menopause can also increase the risk of some chronic illnesses, such as osteoporosis and heart disease. Now a handful of researchers and companies are making a bold claim: collecting and freezing ovarian tissue when one is young and then transplanting it back into the body years later could restore hormone production—putting the onset of menopause on hold, potentially for many years.

潮热、失眠和情绪波动是经历更年期人群面临的令人困扰的症状。尽管这些症状通常是暂时且可治疗的，但更年期还可能增加患慢性疾病的风险，如骨质疏松和心脏病。现在，一些研究人员和公司正在提出一个大胆的主张：年轻时采集并冷冻卵巢组织，数年后再移植回体内，有望恢复激素分泌，从而可能推迟更年期的到来，甚至长达数年之久。

The fact that there are few treatment options for menopause has led some clinicians to propose an unconventional intervention—a technique typically used to restore fertility in people who undergo chemotherapy or who have entered menopause prematurely. A recent modelling study in the American Journal of Obstetrics and Gynecology estimates that reimplanting bits of one's own frozen ovaries every few years could maintain the cyclical hormonal fluctuations that cause menstruation. This could delay the normal onset of menopause potentially for several decades if started in people younger than age 40.

由于更年期治疗手段有限，一些临床医生提出了这种非传统的干预方法。这项技术原本主要用于帮助经历过化疗或过早进入更年期的人群恢复生育能力。近期，《美国产科与妇科杂志》发表的一项建模研究表明，每隔几年重新植入自身冷冻的卵巢组织，可以维持引起月经的周期性激素波动。若40岁以下人群采用此技术，或许能推迟正常更年期数十年。

Outside experts have raised concerns about using this technique to delay menopause in healthy individuals and question whether that goal is necessary in the first place. They say that the potential to reduce the risk of health conditions is oversold. Scientists have also said that existing treatments for menopause symptoms are simpler and safer than this elective procedure, which would require surgically extracting tissue from people in their 20s or 30s, freezing and storing the tissue for decades, and performing multiple surgeries to implant tissue with the goal of maintaining premenopausal hormonal function.

外部专家对这种技术用于延缓健康人群更年期的做法表示担忧，并质疑其必要性。他们认为，该技术降低健康风险的效果被过分夸大。科学家们还指出，这项技术需从二三十岁的人群体内通过手术提取组织，冷冻保存数十年后，再进行多次手术将组织移植回体内，以维持绝经前的激素水平。与此相比，现有的更年期症状治疗方法更为简单且安全。

Still, proponents of the technique say there is a need for new treatment options and that people are already interested. Kutluk Oktay, a reproductive biologist at Yale University and senior author of the nonclinical modelling study, says that about 20 “carefully screened” individuals have opted to store ovarian tissue at his clinic in anticipation of potentially delaying menopause. Those people qualified for select health reasons, including a family history of early menopause and a high risk for menopause-related illnesses. Others who initially banked the tissue for fertility reasons are leaving the option open to use the tissue for menopause delay. “As more proof comes in, it could be that we’re doing it for these general benefits for everybody," Oktay says. “But initially, I think we’re being more selective.”

然而，该技术的倡导者指出，新的治疗方法是必需的，且已经引起了人们的兴趣。耶鲁大学生殖生物学家、该非临床建模研究的主要作者库特卢克·奥克泰指出，约有20名“经过仔细筛查”的个体已经选择在他的诊所储存卵巢组织，以期在未来延缓更年期。这些符合条件的人具有特定的健康状况，如家族中有早更病史或本人易患更年期相关疾病。另一些人最初因生育需求而储存了组织，现在也保留了利用这些组织来延缓更年期的选择。“随着更多证据的涌现，我们或许最终能为所有人带来这些普遍益处，”奥克泰表示，“但起初，我们会更加谨慎地选择适用人群。”

In 2019 more than 100 women from multiple countries seeking menopause and fertility treatments were added to a waiting list to preserve their ovarian tissue for future transplantation, offered by the newly launched company ProFaM Health, based in Ireland. Regulatory delays as well as the pandemic have since stalled the company from enrolling people. “This is very new; I understand that,” says Christiani Amorim, ProFaM Health's chief scientific officer and a fertility researcher at the Catholic University of Louvain in Belgium. Amorim, who has worked on both animal and human ovarian cryopreservation, started to consider the procedure's benefits for humans after witnessing her mother experience severe menopausal symptoms.

2019年，超过100名来自多国、寻求更年期和生育治疗的女性加入了等待名单，目的是储存她们的卵巢组织以备将来移植之用。这项服务由当时新成立的爱尔兰公司ProFaM Health推出。然而，监管延迟和疫情的爆发使得该公司暂停了新客户的招募。“这是一项新兴技术，大家的疑虑我能理解，”克里斯蒂安妮·阿莫林表示，她是ProFaM Health的首席科学官，同时也在比利时鲁汶天主教大学担任生育研究员。阿莫林曾致力于动物和人类卵巢的冷冻保存研究，在亲眼目睹母亲经历严重的更年期症状后，她开始思考这项技术如何能为人类造福。

Maintaining premenopausal hormonal production—the basis of the ovarian tissue transplant technique—could potentially avert some health issues。 The procedure relies on primordial follicles to produce those hormones。 Female babies are born with a fixed number of immature eggs in the primordial follicles in their ovaries。 The ovaries usually eject one egg for potential fertilization each month—using, in a lifetime, only about 500 eggs out of a million or so available。 “If you do the math, 99。9 percent are wasted,” Oktay says。

“They're reserved。” The body produces estrogen when a primordial follicle begins to mature an egg, and then it produces progesterone after ovulation occurs。 Whether or not follicles release an egg, their number declines over time as they are used or naturally degenerate with age。 People reach menopause when the body goes a full year without a period—typically around age 50。 By the time of menopause, very few follicles remain, and hormone production has plummeted。

维持绝经前的激素分泌，这是卵巢组织移植技术的核心，可能有助于预防某些健康问题。该技术依赖于原始卵泡来产生这些激素。女婴出生时，其卵巢中的原始卵泡就携带着固定数量的未成熟卵子。女性一生中，卵巢通常每月排出一个卵子以备受精，因此，在大约一百万个卵子中，实际上只有约500个会被使用。“算一算，99.9%的卵子都被浪费了，”奥克泰说道，“它们其实是储备用的。”当原始卵泡开始使卵子成熟时，身体会分泌雌激素，排卵后则分泌孕激素。无论卵泡是否排卵，其数量都会随时间推移而减少，因为卵子要么被使用，要么随年龄增长而自然衰退。当女性连续一年没有月经，即进入更年期，这通常发生在50岁左右。进入更年期后，卵泡数量锐减，激素分泌也大幅下降。

When someone is younger than age 40, those follicles can be extracted and later transplanted back into the body where they can release mature eggs that could be fertilized—and hormones that could prevent menopausal symptoms. Oktay's research suggests that beyond age 40, the procedure is unlikely to prevent the onset of menopause.

当女性年龄小于40岁时，可以提取这些卵泡，并在数年后将其移植回体内，使其释放可受精的成熟卵子，同时分泌能预防更年期症状的激素。奥克泰的研究表明，对于40岁以上的女性来说，该手术不太可能预防更年期的到来。

The process involves a keyhole surgery through the belly button to strip off part of an ovary's glistening, pearl-like “skin”—a millimetre-thick cortex containing the primordial follicles。 This is “like peeling an orange,” Oktay explains。 The tissue is then sliced into thin slivers, bathed in antifreeze substances in test tubes and preserved in liquid nitrogen, where it awaits transplantation back into the body years later。 Oktay says there is no practical limit for how long the tissue can be preserved and still remain effective。

The process is ultimately the same for those seeking to restore fertility as it would be for those seeking to delay menopause。 To prevent the risk of pregnancy in the latter group, however, the tissue could be grafted to the forearm or abdominal wall instead of in the pelvis, where it could still release hormones into the bloodstream but avoid releasing an egg that could encounter sperm and become fertilized。 The procedure would also prolong menstruation, which few people anticipating menopause would welcome。

该技术通过肚脐进行微创手术，剥离卵巢上闪闪发光的、珍珠般的“皮肤”——这是一层含原始卵泡、厚一毫米的皮质。奥克泰解释说，这就像剥橘子一样。然后将该组织切成薄片，放入试管中的防冻物质中浸泡，并保存在液氮中，等待数年后移植回体内。奥克泰表示，理论上，这种组织无论保存多久都能保持有效。无论是希望恢复生育能力的人，还是希望延缓更年期的人，手术过程都是相同的。然而，为了避免后者怀孕，可以将组织移植到前臂或腹壁，而非骨盆内，这样它仍能将激素释放到血液中，但不会释放卵子从而避免卵子与精子结合受精。不过，该手术还可能延长经期，这却是期待绝经的女性所不愿看到的。

重要词汇

1. menopause n.经绝期

2. ovary n. [植]子房；[解]卵巢

3. fertility n.繁殖力

4. glistening adj.闪耀的,反光的

往期回顾

文章来源 | Scientific American : Experimental Ovarian Tissue Freezing Could Delay Menopause, but Experts Are Weighing the Risks

图片来源 | 百度图片 豆包AI

译者 | 严世龙

译审 | 王春渝、罗晓

复审 | 李小辉

执行编辑 | 罗晓

审核编辑 | 王春渝