Embryo Freezing & Storage
What Is Embryo Freezing?
Embryo freezing, or embryo cryopreservation, is a technique used to preserve embryos for future use. After fertilisation in the IVF process, embryos are cultured in the laboratory and then frozen at a specific stage of development. These embryos can later be thawed and transferred to the uterus in a future treatment cycle.
At Almond Blossoms, we use vitrification, an advanced ultra-rapid freezing method that prevents ice crystal formation. Vitrification offers a supports strong embryo survival during freezing and thawing, compared to the older "slow freezing" technique which had around 80% survival.
Embryo freezing provides flexibility, especially when postponing embryo transfer or preserving fertility due to personal, medical, or legal considerations.
At Almond Blossoms, embryos are frozen exclusively on Day 5 or 6, once they have reached the blastocyst stage.
Extensive clinical evidence supports that freezing embryos at the blastocyst stage results in supports implantation potential without compromising embryo survival. At this stage, the embryo has more than 100 cells and is more resilient during the freezing and thawing process. A minor loss of a few cells is unlikely to affect the embryo’s potential to result in a healthy pregnancy.
Freezing earlier-stage embryos (Days 1–3) may reduce developmental potential after thawing, which is why we focus only on blastocyst freezing to support safe treatment planning.
When Are Embryos Frozen?
Who Should Consider Embryo Freezing?
- Couples undergoing IVF who wish to postpone embryo transfer (e.g., for medical recovery, career or travel).
- Patients at risk of Ovarian Hyperstimulation Syndrome (OHSS).
- Individuals who want to store surplus embryos for future use.
- Couples undergoing Preimplantation Genetic Testing (PGT) – in these cases, freezing is mandatory, as the genetic test results are not available immediately.
- Cancer patients preserving fertility before treatment.
- Couples building a family progressively over time (e.g., spacing pregnancies).
What Is Vitrification?
Vitrification is a rapid-freezing technique that turns cells into a glass-like state in milliseconds. This prevents the formation of ice crystals that can damage the delicate structures of the embryo.
Key Advantages
- Supports good post-thaw viability.
- Excellent outcomes for blastocyst-stage embryos.
- Consistent with ESHRE and ASRM guidelines as the gold standard in cryopreservation.
Considerations & Success Rates
- Embryo survival depends on embryo quality and stage of development.
- Blastocyst-stage embryos are more robust during freezing/thawing.
- Research supports the possibility of pregnancy from vitrified embryos at the blastocyst stage.
- There is no increase in congenital anomalies among babies born from frozen embryos.
Storage Duration in the UAE
Embryos are stored in liquid nitrogen at −196°C. In the UAE:
- The initial storage duration is 5 years, with mandatory annual renewals.
- Extensions for another 5 years is possible.
Future Use
When you are ready, your embryos can be thawed and transferred during a natural or medicated frozen embryo transfer (FET) cycle. Success depends on:
- Your age at the time of egg collection
- Embryo quality
- Uterine receptivity at the time of transfer