Egg / Sperm / Embryo Freezing 凍卵 凍精 凍胚介紹

Egg Freezing 凍卵

What Is Egg Freezing?

You may have heard of egg freezing (also known as oocyte cryopreservation) but are unsure what it really means. A woman is born with a finite number of eggs, and both egg quantity and quality decline with age—this is a natural, irreversible process.

Egg quality is a key factor affecting pregnancy and live birth rates. After age 34, the likelihood of chromosomal abnormalities in eggs increases year by year. Freezing healthy eggs at a younger age offers women an opportunity to take control of their fertility and create a safeguard for future family planning.

Key Considerations for Egg Freezing

Ideal Age for Egg Freezing: 34 and Younger for Best Results

Age and ovarian reserve are critical factors in egg freezing.
35 is often seen as a turning point for female fertility.
Freezing eggs before this age—ideally around 34 or younger—can maximize success rates. It's generally recommended to retrieve at least 10 to 15 eggs to increase the chance of future pregnancy.

• The egg freezing process is safe with extremely low risk of complications.

• Marriage is not required to undergo the procedure.

• The entire process usually takes 2–3 weeks, allowing for flexible life planning without rushing into parenthood.

Who Should Consider Egg Freezing?

Egg freezing is suitable for the following groups:

• Women with no uterus or uterine dysfunction, awaiting legal surrogacy options

• Women over 34 (especially 35+) who are not yet planning pregnancy

• Those requiring ovarian surgery, chemotherapy, or radiation therapy

• Women with a family history of premature ovarian failure or autoimmune diseases

• In cases where the partner cannot provide sperm or has azoospermia on the day of retrieval, eggs can be frozen temporarily for later fertilization

Egg Freezing Process: Step-by-Step

Step 1: Pre-Treatment Assessment

Before starting egg freezing, your fertility potential is evaluated using blood tests and ultrasound to assess ovarian function:

AMH Test (Anti-Müllerian Hormone)

• AMH is secreted by small ovarian follicles.

• It indicates the size of the egg reserve, and levels do not fluctuate during the menstrual cycle.

• Normal AMH range: 2–5 ng/mL

  • AMH > 5: may indicate PCOS

  • AMH < 2: may suggest diminished ovarian reserve

FSH Test (Follicle Stimulating Hormone)

• Taken on day 2–3 of the menstrual cycle

• FSH stimulates follicle development

• FSH < 10: normal ovarian reserve
  FSH 10–20: reduced ovarian function → early freezing recommended

Transvaginal Ultrasound (Day 3–5 of Cycle)

• Assesses uterus for fibroids or endometriosis

• Counts ovarian follicles to estimate remaining egg supply

Step 2: Ovarian Stimulation

• In a natural cycle, only one egg typically matures and is released.

• During egg freezing, hormone injections stimulate multiple follicles to mature simultaneously.

• Injections begin on day 1–3 of your period, with follow-up ultrasounds and blood tests to monitor progress.

Note:
Injections are usually administered subcutaneously (under the skin), ideally in areas with more fat (abdomen, hips). Rotate injection sites to avoid hard lumps.

Step 3: Monitoring Follicle Growth

• On days 8–9 of the cycle, visit the clinic to check follicle size.

• Continued injections, blood tests, and ultrasounds are done 2–3 times to determine the best time for retrieval.

Step 4: Egg Retrieval

• Once follicles mature, the doctor will schedule an egg retrieval, usually 36 hours after a final "trigger shot."

• The procedure is performed transvaginally under sedation.

Step 5: Egg Freezing (Cryopreservation)

• Eggs are rapidly frozen using vitrification, a state-of-the-art flash-freezing method.

• This technique dehydrates and rapidly cools the eggs to prevent damaging ice crystals.

• Eggs are stored at –196°C in liquid nitrogen, significantly improving survival and quality after thawing.

Step 6: Post-Retrieval Follow-Up

• If needed, additional egg retrieval cycles can be arranged.

• The full process takes about 2–3 weeks, with 3–5 clinic visits.

• Some clinics now offer long-acting stimulation injections to reduce injection frequency and clinic visits—perfect for busy professionals balancing career and fertility goals.

Consult with your fertility specialist to tailor a treatment plan that suits your health, goals, and lifestyle.

Sperm Freezing 凍精

What Is Sperm Freezing (Semen Cryopreservation)?

Sperm freezing, or semen cryopreservation, is the process of collecting, processing, and preserving sperm in liquid nitrogen at –196°C. When needed, the sperm is thawed and used in assisted reproductive techniques such as in vitro fertilization (IVF). This temporary storage of sperm is what we commonly refer to as sperm freezing.

Who Should Consider Freezing Their Sperm?

Medical Reasons:

• Before undergoing cancer treatments such as chemotherapy or radiation

• Men with consistently poor semen analysis results

• Those taking psychiatric medications, hormonal therapies, blood pressure medications, or other drugs that may impair fertility

Other Reasons:

• Men who plan to undergo vasectomy but still wish to preserve future fertility

• Those who are not currently planning to have children but may want to in the future

• Men exposed to high-risk environments, such as radiation, chemical solvents, or high temperatures (e.g., certain industries or military work)

• In cases where the male partner is unable to provide a sperm sample at the time of assisted reproduction treatment (e.g., IVF or IUI)

Do I Need to Freeze My Sperm?

Male infertility is becoming increasingly common, yet often shows no obvious physical symptoms. Many men are unaware of potential issues until they undergo a semen analysis.
If you're concerned about age, future health conditions, or fertility risks, you may want to proactively undergo a semen analysis and consult a fertility specialist about sperm freezing.

Sperm Freezing Process

Step 1: Fertility Clinic Consultation

• Schedule a consultation with a fertility specialist (e.g., at Lee Women's Hospital in Taichung).

• You'll be asked to abstain from ejaculation for 3–5 days (but no more than 7) prior to sample collection.

• The doctor will walk you through the sperm freezing process and assess your needs.

Step 2: Semen Collection and Analysis

You may collect the sample either inside or outside the clinic:

• In-clinic collection: The sample is produced in a private collection room and submitted directly to the fertility lab.

• At-home collection: The sample is collected in a sterile container and delivered to the fertility center at room temperature as soon as possible.

The sample is then tested by the fertility lab:

• If sperm quality is acceptable, the sample undergoes gradient-density centrifugation, a method to purify and concentrate motile sperm in preparation for freezing.

• If the sperm quality is suboptimal, your physician will recommend appropriate lifestyle changes, nutritional support, or medical treatment to improve outcomes for future freezing.

Step 3: Sperm Cryopreservation

Once the sperm is processed, it is cryopreserved in liquid nitrogen at –196°C using standardized laboratory protocols. This enables long-term storage and maintains sperm viability for future use in fertility treatments.

Embryo Freezing 凍胚

What Is Embryo Freezing (Cryopreservation)?

Embryo freezing, also known as frozen embryo preservation or cryopreservation of embryos, involves storing fertilized embryos in liquid nitrogen at –196°C. At a suitable time based on the patient's physical condition and medical guidance, the frozen embryos are thawed and transferred into the uterus.

For couples who are not yet ready for pregnancy—due to health reasons or family planning—freezing embryos now and transferring them later may improve the chances of success when the time is right.

A Closer Look at Embryo Freezing Technology: Vitrification

The most advanced technique used in embryo freezing is vitrification, or ultra-rapid freezing. Unlike traditional slow-freezing methods, vitrification transforms the embryo into a glass-like solid state, avoiding the formation of ice crystals that can damage internal cell structures.

The biggest concern when freezing embryos is the risk of ice crystals forming inside the cells, which may rupture organelles and compromise cell function, or even lead to embryo death. Vitrification minimizes this risk.

Who Should Consider Embryo Freezing?

Medical Reasons:

• Premature ovarian insufficiency (POI)

• Polycystic ovary syndrome (PCOS)

• Hormonal imbalances that affect implantation

• Undergoing chemotherapy or ovarian surgery

Family Planning Reasons:

• Delay in pregnancy due to personal or career reasons

• Planning for a second child in the future

• Subject to embryo transfer limits during IVF treatment cycles

According to Taiwan's Assisted Reproduction Act, embryos can be stored for up to 10 years. Couples with future fertility plans are encouraged to prepare early, especially to avoid the risks of advanced maternal age.

Embryo Freezing Process

Step 1: Pre-treatment Evaluation

Before starting the embryo freezing process, both partners undergo fertility and health assessments. If results are satisfactory, the procedure is scheduled. If not, the doctor will recommend pre-treatment adjustments.

For women:

• Hormonal blood tests: AMH (ovarian reserve), FSH, etc.

• Transvaginal ultrasound: follicle count and ovarian health

For men:

• Semen analysis: sperm count, morphology, and motility

Step 2: Ovulation Stimulation

After evaluation, your doctor will prescribe a customized stimulation plan. Generally, ovarian stimulation starts on Day 2 or 3 of the menstrual cycle with hormonal injections to promote follicle growth.

You'll receive:

• Medication guidance and injection training

• Ongoing blood tests and ultrasounds to adjust dosage

• Around 2–3 follow-up visits to monitor follicular development

Step 3: Egg and Sperm Collection

Egg Retrieval:

• Once follicles are mature, a trigger shot is given.

• 36–40 hours later, eggs are collected under general anesthesia through a transvaginal aspiration procedure (approx. 10 minutes).

• Patients can usually go home the same day after recovery.

Sperm Collection:

• The male partner must abstain from ejaculation for 3 days before providing a semen sample.

• On the day of egg retrieval (8:00 AM), the fresh sample is delivered to the fertility lab at the hospital.

Step 4: Fertilization

Mature eggs and sperm are sent to the embryology lab, where skilled embryologists perform in vitro fertilization (IVF). Successfully fertilized embryos are then cultured in strictly controlled incubators (humidity, temperature, CO₂ levels) for 1–5 days.

If Preimplantation Genetic Testing for Aneuploidy (PGT-A) is required, inform your doctor in advance. Embryos will be cultured to Day 5 (blastocyst stage), biopsied, and sent to a genetics lab for analysis.

Step 5: Embryo Cryopreservation

Viable embryos are cryopreserved using vitrification. During this process:

• High-concentration cryoprotectants remove water from inside the cells

• Embryos are flash-frozen and stored in liquid nitrogen at –196°C

They remain safely stored until a future embryo transfer is planned.