伊丽莎白生育中心

Egg freezing, also known as oocyte cryopreservation, involves the extraction and preservation of a woman's eggs for future use.

The eggs are collected through a process known as ovarian stimulation, where hormone medications are administered to stimulate the ovaries to produce multiple eggs. Once the eggs have matured, they are retrieved and cryopreserved by rapidly cooling them to sub-zero temperatures. This freezing process halts biological activity, effectively preserving the eggs until they are ready to be used.

Egg freezing is an increasingly viable option for women who wish to delay childbearing for various reasons. In Singapore, egg freezing for medical reasons is allowed. From July 2023, elective egg freezing is also allowed for women aged 21 – 37, regardless of marital status.

Learn more about elective egg freezing below, or read our comprehensive guide to understand how it can benefit you.

Reasons for elective egg freezing

Cancer patients undergoing chemotherapy: Elective egg freezing offers a valuable opportunity for cancer patients who are about to undergo chemotherapy. Chemotherapy treatments can have detrimental effects on fertility, potentially compromising the ability to conceive in the future. By freezing their eggs before chemotherapy, cancer patients can safeguard their reproductive potential and increase the chances of starting a family after their treatment is completed.

Medical treatment that could affect fertility: Certain medical treatments, such as radiation therapy or surgical procedures, can have adverse effects on fertility. Elective egg freezing allows individuals undergoing such treatments to preserve their eggs for future use, mitigating the potential risks to their reproductive health.

Preserving younger eggs for future use: Elective egg freezing is an advantageous option for individuals who wish to preserve their fertility while they are still young. Women are born with a finite number of eggs, and as they age, the quantity and quality of these eggs naturally decline, making conception more challenging. By electively freezing their eggs at a younger age, individuals can effectively "pause" their biological clock and preserve the vitality of their eggs, ensuring a higher likelihood of successful pregnancies in the future.

Benefits for egg freezing

• Increased chances of future conception in family planning
• Flexibility to use eggs when ready
• Alleviates pressure and stress related to personal choices, priorities, lifestyle, career, and finances
• Provides more time to find the right partner and form a family
• Protects eggs from health conditions like cancer and treatments such as chemotherapy and radiation

Risks and complications for egg freezing

Failure to complete treatment as a result of:

• Poor follicular response
• Absence of eggs during oocyte retrieval
• Only mature eggs can be frozen

Operative risks as a result of:

• Infection
• Bleeding

Potential side effects of ovarian hyperstimulation syndrome (OHSS):

• Cramps / pain
• Swelling / bloat
• Hospitalisation / albumin infusions / abdominal tapping

Thaw survival rate:

• Approximately 90 – 97% of eggs survive the thawing process.

Risks for patients aged 45 and above:

• Increased risk of genetic abnormalities in the child
• Possible health or physical/mental impairments in the child due to advanced maternal age during pregnancy
• Considerations of physical and financial ability to care for the child until adulthood, taking into account the couple's health, older age, and the cost of raising a child as they grow older
• Potential impact of advanced parental age on the welfare of the child, including social acceptance, a large age gap between parents and the child, and the possibility of the child having to care for aged/ill parents or facing the loss of one or both parents during their schooling years or early in their careers

Our elective egg freezing services

At Mount Elizabeth Fertility Centre, our skilled fertility specialists have a wealth of experience in managing various fertility treatments including elective egg freezing.

Learn more about our bundles and fees for EEF services.

EmbryoScope 延时系统是一项用于密切监测胚胎发育的创新技术。该系统与培养箱、高分辨率摄像机和集成计算机软件配合使用，可提供长达 135 小时的逐分钟显微视频，不间断记录胚胎的生长过程。

EmbryoScope 的优点

使用 EmbryoScope 的好处包括以下几点：

减少对胚胎的干扰和处理

由于采用了延时系统，不需要将在 EmbryoScope 内孵育的胚胎取出进行分析。

全面的胚胎分析和监测

胚胎学家可通过内置摄像头拍摄的高质量图像和视频（长达 7,200 分钟）监测和分析胚胎的发育和关键形态特征。EmbryoScope 可显示标准胚胎培养过程中可能无法发现的异常情况。

优化胚胎选择和排序

通过 EmbryoScope 获得的深入而准确的数据提供了胚胎的全面可视化发育情况​​，有助于胚胎选的选择和排序。我们的胚胎学家能够识别出最高质量的胚胎用于移植或冷冻保存，从而增加了健康怀孕的机会。

我们使用磁性激活细胞分选 (MACS) Annexin V 系统来选择精子，该系统可将健康的精子与因 DNA 碎片化程度高而开始凋亡（细胞死亡）的精子分离开。

经过纯化的精子群在形态学、活动性、DNA 完整性和冷冻存活率方面具有更高的总体质量，因而可以产生更高的精子受精潜力和良好的胚胎或囊胚。

MACS 的优点

MACS 可以使以下患者受益：

• 前几个周期的受精率低
• 前几个周期的胚胎质量差
• 精子参数异常
• 精索静脉曲张（阴囊内静脉扩张）
• 癌症（通过在化疗或放射治疗前后保留生育能力）

除了我们在常规精液分析中评价的参数外，还有一些其他诊断测试有助于更深入地了解精子健康状况。

这些测试包括：

DNA 碎片化检测

精子的 DNA 碎片化与精子中遗传物质的完整性相关，而高 DNA 碎片化可以解释不孕不育、反复流产和体外受精结果不佳。

导致高 DNA 碎片化的主要因素是与年龄较大、酒精、饮食、睾丸温度升高、感染、职业污染物、吸烟、压力和精索静脉曲张（阴囊内静脉扩张）相关的氧化应激。

DNA 碎片化测试可通过检测精子内的异常遗传物质，在分子水平上提供可靠的精子分析，从而帮助识别有生育力低下风险的男性。

透明质酸结合分析 (HBA)

透明质酸结合分析 (HBA) 可评估精子的成熟度。透明质酸 (HA) 是一种围绕卵子的糖分子，只有成熟的精子才能与其结合。能与 HA 结合的精子其精子发育成熟度更高，包括更少的染色体异常和更高的精子 DNA 完整性。

HBA 测试是精子分析的另一个组成部分，能够可靠地诊断疑似男性不育，并预测精子性能和受精潜力。

Oxisperm 测试

Oxisperm 测试可评估精子的氧化应激水平。精子中的高氧化应激水平表明活性氧类 (ROS) 水平升高，而这对精子的 DNA 完整性和活动性有直接的负面影响。接触烟草、酒精、家用电器、辐射（来自笔记本电脑、电视和紫外线）和重金属等物质可导致 ROS 水平升高。

氧化应激是指 ROS 的产生与身体通过抗氧化剂中和其有害影响的能力失衡。精子极易受到氧化应激的影响，在这种情况下，精子质膜会出现过氧化损伤，从而导致 DNA 碎片化。

高氧化应激与精子活动性和功能不佳相关，而这可导致胚胎形成不良、流产和不孕不育。精索静脉曲张、感染、炎症和脊髓受伤等疾病也与氧化应激引起的不孕不育相关。

这些诊断前测试提供的信息不仅有助于男性生育能力的临床诊断、管理和治疗，还可增加辅助生殖程序的有利结果。

可从这些测试中获益的患者可能存在一些指示性因素，例如：

• 年龄较大
• 多次体外受精/ICSI（卵胞浆内单精子注射）治疗失败
• 囊胚发育不良
• 反复流产
• 不明原因的不孕不育
• 精索静脉曲张

我们严格的实验室标准和理想的培养条件使我们能够支持胚胎生长到囊胚阶段。

将胚胎发育到囊胚阶段的能力使我们能够在移植时选择最健康、最有可能着床的胚胎。

仅需移植 1 个或 2 个囊胚，而传统方法是将 3 个或 4 个早期胚胎移植回母体。这降低了体外受精的多胎风险，同时提高了怀孕率。

我们的首席胚胎学家 Ng Lai Cheng 女士 自 1993 年以来一直从事囊胚培养工作，她最初是一个研究囊胚培养和移植的动物研究共培养团队的成员，后来从事临床胚胎学工作。

接受体外受精治疗时卵巢反应不佳的患者可以通过双重刺激方案获得新的希望。卵巢反应不佳可能由多种因素引起，包括卵巢储备减少或年龄较大。

在传统体外受精程序中，仅在月经周期的早期卵泡期，使用轻度卵巢刺激进行 1 次卵母细胞提取（卵子采集）。在双重刺激方案中，医生会在黄体期进行第二次卵母细胞提取。

在同一月经周期的卵泡期和黄体期进行双重刺激，可有更大的机会提取更多的卵母细胞。这可以提高获得优质囊胚的几率，从而增加怀孕成功率。

我们常规应用一种称为“冷冻所有体外受精”的实验室技术，这种技术为众多夫妇提供了比以往更多的选择。

玻璃化是一种安全冷冻囊胚的方法。它可以避免形成会对冷冻胚胎造成极大伤害的冰晶。

体外受精过程中的玻璃化不仅可提高解冻胚胎的存活率，还可改善冷冻移植程序后的怀孕率。这意味着更好的妊娠结局和更低的产科并发症（如早产或胎儿生长受限）发生率。

治疗周期结束后剩余的优质囊胚（第 5 天或第 6 天晚期胚胎）将通过玻璃化保存以供将来使用。

冷冻所有囊胚策略对以下女性特别有益：

• 被诊断为卵巢储备低下
• 在体外受精治疗期间卵巢反应不佳
• 年龄较大
• 希望在接受癌症治疗前保留生育能力的癌症患者