What are Frozen Embryos?

Frozen Embryos: Preserving Fertility at the Optimal Time for the Future
Frozen embryos are embryos that have been successfully fertilized and well developed during an IVF cycle. Through advanced vitrification techniques, they are preserved long-term in an ultra-low temperature environment (liquid nitrogen). This efficient preservation method stabilizes metabolic activity and cellular structure, maintaining optimal viability.

When a couple is ready to conceive, thawed embryos can be implanted directly into the uterus, increasing the chance of pregnancy and reducing the stress of repeated treatments. This is especially suitable for couples not planning to conceive immediately but wish to preserve fertility for the future. Take advantage of your fertility’s golden window—preserve now to ensure future success.

Frozen embryos are like “seeds of fertility” saved for the future.

Global Trends in Embryo Freezing

With advances in reproductive medicine, more and more couples around the world are choosing to postpone pregnancy by freezing embryos. According to the American Society for Reproductive Medicine (ASRM), the success rate of frozen embryo transfers has steadily increased, and it has become one of the mainstream options in assisted reproduction. Cryopreservation not only helps preserve embryo quality but also enables better selection of healthy embryos—offering more flexibility for life planning.

The Frozen Embryo Process: From Preservation to Preparing for New Life

1. Embryo Culturing and Selection: Choosing the Hope for the Future

   In an IVF cycle, fertilized eggs are cultured in a laboratory for several days until they develop into embryos. Embryologists carefully select the best embryos based on morphology, development rate, and other indicators, then cryopreserve them to increase future pregnancy chances.

   

   Embryo culture and selection are key steps before freezing.

2. Vitrification Technology: Freezing Hope, Preserving Vitality

   At Huayu, we use advanced vitrification to rapidly freeze embryos at ultra-low temperatures, preventing ice crystal formation that could damage cells. This technique maximizes viability and structural integrity, supporting future implantation success.

3. Safe Storage: Safeguarding Every Frozen Embryo

   Frozen embryos are stored in liquid nitrogen tanks at approximately −196°C, completely halting metabolism. For instance, embryos frozen at age 30 and implanted ten years later retain the pregnancy rate of a 30-year-old. For those not ready to conceive now, egg or embryo freezing offers future possibilities. Huayu ensures 24/7 monitoring so every embryo is kept under the safest, most reliable conditions.

   

   Strictly controlled liquid nitrogen storage protects embryo quality.

4. Thawing and Transfer: A Key Step Toward New Life

   When you’re ready, embryos are thawed and carefully handled by embryologists. Doctors and patients schedule the optimal transfer time based on evaluation. The procedure is similar to fresh embryo transfer and is usually painless in an outpatient setting—no hospitalization required. Each frozen embryo holds the hope of future happiness.

The beginning of new life.

Preparations and Precautions Before Embryo Transfer

To improve implantation and pregnancy success rates, the medical team evaluates the following before transfer:

• Endometrial condition: Ensure endometrial thickness is ideal for implantation (usually ≥ 8 mm).
• Hormone levels: Optimize estrogen and progesterone to support implantation.
• Lifestyle adjustments: Maintain regular routines, moderate exercise, and avoid stress or staying up late.
• Post-transfer care: Get sufficient rest, avoid heavy lifting, follow-up as instructed. If you have concerns, contact us via LINE anytime.

Process comparison of frozen vs. fresh embryo transfer.

Pregnancy rates by age group with PGT-A.

Advantages of Frozen Embryos: Comprehensive Preparation for Future Fertility

• Preserve fertility, keep options open: Ideal before cancer treatment, chemotherapy, or radiation—preserve the hope of future parenthood.
• Boost IVF success rates: Transferring when uterine conditions are optimal can even outperform fresh transfers.
• Flexible timing: Choose the best time based on life plans and health—no pressure to conceive immediately.
• Avoid repeat egg retrieval: If multiple good embryos are created, freezing avoids repeated surgeries and costs.
• Reduce multiple pregnancy risk: Single Embryo Transfer (SET) helps protect both mother and baby.

Differences Between Egg Freezing and Embryo Freezing

Many wonder about the difference—here’s a quick comparison to help you choose the best option.
Note: Embryo freezing requires a legal marriage (per Taiwan regulations).

Comparison between frozen eggs and embryos.

Freezing embryos isn’t just storage—it’s reserving a chance to create life for your future self. Whether for personal plans or medical needs, embryo freezing is a safe and reliable option.

Who Should Consider Freezing Embryos?

• Not planning pregnancy now but want to preserve fertility: Due to work, studies, or personal plans.
• Have multiple good embryos in IVF: Freeze extras for future use to improve cumulative success and reduce repeat treatment burden.
• Uterus not ready for transfer yet: Thin endometrium, intrauterine fluid, or polyps—freeze first, transfer after optimization.
• At risk for OHSS (ovarian hyperstimulation syndrome): Freeze-all strategy, transfer later when recovered.
• Facing fertility-impacting treatments: e.g., chemotherapy or radiation—freeze embryos beforehand.

Cost and Storage Duration of Frozen Embryos

Costs usually include:

• Clinic visits: 3–4 visits before egg retrieval; follow-ups after transfer.
• Medication & injections: Vary by individual condition and AMH levels.
• Egg retrieval & embryo transfer fees: Depend on the number of eggs, procedures performed.
• Freezing (vitrification) fee: Processing fee for cryopreserving embryos.
• Annual storage fee: Yearly storage management fee.
• Thawing & transfer fee: Charged when you decide to use frozen embryos.

Costs vary by treatment plan and number of embryos. Please contact Huayu for a personalized consultation.

By law (Taiwan’s Assisted Reproduction Act), embryos can typically be stored for up to 10 years. For full details and application steps, consult our team.

FAQ – Frequently Asked Questions

Frozen embryos are an important option for preserving fertility. Below are common questions about process and success factors.

• Does freezing affect embryo quality?

  Modern vitrification rapidly freezes embryos to prevent ice crystal damage. Studies show thawed embryos have similar survival and development potential as fresh ones.

• Is the success rate of frozen embryos high?

  At Huayu, high-standard freezing and thawing protocols yield success rates comparable to fresh transfers—sometimes higher. Factors include age, embryo quality, and uterine condition.

  

  Live birth rates by age group with frozen embryos.

• How long can frozen embryos be stored?

  Technically, embryos can be stored long-term without quality loss. In Taiwan, the legal limit is 10 years.

• Is special care needed after thawing?

  Embryologists evaluate thawed embryo viability. After transfer, follow your doctor’s instructions: rest, eat well, manage stress, and attend check-ups.

Common Myths and Facts About Embryo Freezing

• Myth: Embryos degrade if frozen too long

  Fact: Vitrification preserves embryos long-term without quality loss; storage duration shows no adverse effect on success rate.

• Myth: Babies from frozen embryos are less healthy

  Fact: Studies worldwide confirm babies from frozen embryos are as healthy and develop normally.

• Myth: Freezing increases miscarriage risk

  Fact: With a well-prepared uterine environment, implantation and ongoing pregnancy rates are comparable to fresh transfers.