Embryo freezing lets you preserve high-quality embryos from an IVF cycle for use months or even years later — without repeating the stimulation and retrieval process. Thai fertility clinics use the same vitrification technology as the world's top laboratories, achieving post-thaw survival rates above 95%, at a cost that makes building your family more affordable.
What Is Embryo Freezing?
Embryo cryopreservation stores embryos in liquid nitrogen using vitrification — a rapid-freezing method that prevents ice crystal formation and preserves cellular structure. Vitrified embryos can be stored indefinitely and perform as well as fresh embryos, providing additional chances at pregnancy without repeating stimulation.
Post-thaw survival rates exceed 95% with modern vitrification, and frozen embryo transfers achieve pregnancy outcomes comparable to fresh cycles. Embryos are typically frozen at the blastocyst stage after careful grading, and each is stored on an individually labelled device with strict double-witnessing protocols.
Common Concerns Embryo Freezing Can Address
- You have surplus embryos from an IVF or ICSI cycle
- You want to preserve embryos before medical treatment that may affect fertility
- Your fresh transfer was postponed due to OHSS risk or other medical reasons
- You're waiting for PGT-A or PGT-M genetic testing results before transfer
- You want to space pregnancies without repeating a full IVF cycle
Are You a Good Candidate?
- Currently undergoing or have completed an IVF or ICSI cycle with surplus embryos
- Embryos have reached blastocyst stage (day 5–6) or are of sufficient quality for freezing
- Willing to pay annual storage fees to maintain frozen embryos
Techniques & Options
Embryo freezing is performed by the embryology team in the laboratory and does not require any additional procedure on the patient. The key decision is timing — at what stage of development the embryos are frozen — and the vitrification technique used.
Each embryo is assessed individually, and only those meeting quality thresholds are recommended for freezing:
Blastocyst Vitrification (Day 5–6)
The most common approach in modern IVF. Embryos are cultured to the blastocyst stage — day 5 or 6 — before being vitrified. Blastocysts have a higher implantation potential than earlier-stage embryos, and the extended culture period allows the embryology team to select the strongest candidates for freezing.
- Highest survival rates after thawing (above 95%)
- Better selection of viable embryos
- Standard practice at leading Thai fertility clinics
Cleavage-Stage Freezing (Day 2–3)
In some cases, embryos are frozen at the cleavage stage — day 2 or 3 — when they have 4–8 cells. This may be recommended if only a few embryos are available and the embryologist wants to avoid the risk of losing them during extended culture, or in specific clinical scenarios.
- Suitable when few embryos are available
- Avoids the risk of embryo arrest between day 3 and day 5
- Slightly lower implantation rates compared to blastocyst transfer
Recovery Timeline
Embryo Assessment
After fertilisation, your embryology team monitors embryo development daily using time-lapse imaging. They assess cell division, symmetry, and fragmentation to grade each embryo. Only embryos meeting quality criteria are selected for vitrification.
Vitrification
Selected embryos are treated with cryoprotectant solutions and then plunged into liquid nitrogen at -196°C. The entire vitrification process takes just minutes per embryo. Each embryo is stored on an individually labelled device (straw or cryotop) for precise identification.
Secure Storage
Vitrified embryos are stored in monitored liquid nitrogen tanks at the clinic. Storage systems include 24-hour temperature monitoring and alarm systems. Your clinic will contact you annually to confirm continued storage and collect the storage fee.
Thawing & Transfer
When you're ready for a transfer, embryos are warmed rapidly using a controlled thawing protocol. Survival rates exceed 95% with modern vitrification. The surviving embryo is transferred to your prepared uterus in a simple, painless procedure — a frozen embryo transfer (FET) cycle.
What to Expect
Safety & Risks
Embryo freezing is one of the safest and most routine procedures in assisted reproduction. The risks are minimal and relate primarily to the storage and thawing process rather than to any procedure on the patient.
- A small percentage of embryos may not survive the thawing process (under 5%)
- Equipment failure or power outage — mitigated by 24-hour monitoring and backup systems
- Administrative error in labelling — minimised by strict double-witnessing protocols
- No guarantee that frozen embryos will result in a pregnancy when transferred
- Emotional stress related to decisions about stored embryos over time
Leading Thai fertility clinics follow strict international protocols for embryo identification, storage, and quality assurance. Double-witnessing — where two embryologists independently verify the identity of every embryo at each step — is standard practice, in line with ESHRE and HFEA guidelines.
How Much Does Embryo Freezing Cost in Thailand?
Our pricing is transparent and covers the full vitrification process and first-year storage — no hidden fees.
Embryo Freezing
Embryo freezing package- Embryologist consultation
- Embryo assessment & grading
- Vitrification procedure
- First year of storage
- Ongoing storage coordination
- Dedicated care coordinator
Common Questions About Embryo Freezing
Everything you need to know before your procedure
Dr. Natthida Chaisiri
MEDICALLY REVIEWEDFertility Specialist · Bangkok
Last reviewed: March 8, 2026
What's Included
- Embryologist consultation
- Embryo assessment & grading
- Vitrification procedure
- First year of storage
- Ongoing storage coordination
- Dedicated care coordinator
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