Vitrified Donor Oocytes for IVF Clinics: What an International Egg Bank Does

Short answer: an international egg bank evaluates donors, vitrifies their oocytes (cools them into a glass-like state without ice), stores them under documented cryogenic conditions and coordinates how they are used: to create embryos in licensed laboratories, or to supply vitrified oocytes to an authorized clinic. A systematic review found vitrification superior to slow freezing for cryosurvival (moderate-quality evidence) and for clinical outcomes (low-quality evidence) in oocytes and embryos [1].

Behind every donor egg cycle there is a chain most patients never see: donor screening, vitrification, cold storage, paperwork and a shipment that has to arrive intact. The bank is the organization that runs that chain. If you run an IVF clinic, this article explains each link, which numbers deserve a second look, and what the CELAGEM International Egg Bank does at the center of it.

What is an international egg bank?

It is a program that works with frozen donor eggs instead of fresh ones. Because the oocytes are vitrified ahead of time, the donor’s stimulation and the recipient’s cycle do not have to be synchronized, and the oocytes can travel to the place where the treatment will happen. A published comparison of sibling oocytes from the same donation cycles, 35,654 oocytes in total, found that outcomes with vitrified and fresh oocytes were comparable once the number of oocytes available after warming was the same [2]. The authors also noted that this came from experienced embryologists with consistently high survival, so the laboratory matters.

How it works, step by step

In general terms, the path of a vitrified donor oocyte looks like this:

1. Donor selection and evaluation against medical criteria.
2. Vitrification of the oocytes after retrieval.
3. Cryogenic storage with traceability: every device is identified and its storage conditions are documented.
4. Documentary review of origin and destination requirements.
5. Logistics: coordinated shipment to an authorized clinic, or use in a licensed laboratory to create embryos.
6. Warming and IVF at the receiving center, which decides the clinical plan.

The three CELAGEM modalities

• Embryo creation. Options for creating embryos in licensed laboratories.
• Supply of vitrified oocytes. We coordinate the shipment of vitrified oocytes to an authorized clinic, according to origin and destination requirements.
• Tailored international program. Documentary evaluation, traceability and logistics coordination, always subject to the authorization of the receiving center.

The bank works with genetics, embryology and reproductive biotechnology, and provides technical support, donor selection and international coordination according to each country’s requirements. CELAGEM works from Bogotá, Medellín and Buenos Aires.

Numbers the bank reports, and how to read them

CELAGEM reports a 98% oocyte survival rate after warming and a blastulation range of 45% to 60%. These are reported laboratory figures. They describe how oocytes and embryos behave in the lab. They are not the probability that any one patient will have a baby, and they should never be read that way.

It is also fair to ask any bank how it defines and counts its numbers. Survival after warming is not the same everywhere: in one published cohort of 273 couples treated at two Italian centers with vitrified oocytes imported from three banks, average survival after warming was 86% [3]. Ask what the denominator is, which donors and which period are included, and who counted.

The blastocyst stage matters because of what happens next. In a retrospective study of 1,178 warming cycles from a cryopreserved donor oocyte bank, the authors found a benefit to extended culture and blastocyst transfer compared with cleavage-stage transfer, even when only one or two quality embryos were available early [4]. It is an observational result, not a promise, but it explains why blastulation is one of the numbers worth watching.

Why traceability and the cryogenic chain matter

Oocytes may stay in storage for a long time, and storage equipment can fail. A 2026 bench study that induced a vacuum failure in a liquid nitrogen tank found that monitoring vacuum integrity and nitrogen weight flagged the deterioration before the conventional temperature alarm did [5]. The practical lesson for a clinic is simple: a bank should be able to show how each oocyte is identified, where it is stored and how that storage is monitored. That documentation is part of what we coordinate with receiving centers.

Why 8 vitrified oocytes?

CELAGEM offers a program of 8 vitrified oocytes as a proposal with embryological support. The number is not arbitrary. In the Italian cohort above, the authors concluded that the larger the group of imported vitrified oocytes allocated to a recipient, the more efficiently each cycle can be managed, and they recommend at least eight per couple [3]. The study was retrospective, and the authors call for confirmation in more centers. The program is a plan with embryological backing. It does not promise pregnancy.

For clinics: a tailored program

If you run a clinic and need vitrified donor oocytes, the program starts with a documentary evaluation of origin and destination requirements. Then come traceability and logistics coordination. Whether a shipment can go ahead depends on those requirements and on your center’s authorization. We evaluate each case and explain the conditions and costs. Request a clinic partnership and write to our team to schedule an evaluation.

Frequently asked questions

What does vitrified mean?

Vitrification cools oocytes so fast that they solidify into a glass-like state without forming ice crystals. A systematic review found it superior to slow freezing for cryosurvival (moderate-quality evidence) [1].

Can frozen donor eggs be shipped to any country?

No. Shipments depend on the requirements of the country of origin and the country of destination, and on the authorization of the receiving clinic. We review each case individually.

Do the lab rates tell a patient her chances of a live birth?

No. Survival and blastulation rates describe laboratory performance. Individual outcomes depend on many factors that the treating team evaluates.

Does a registered donor profile mean the donor is available?

No. A registered profile and an available donor are different things, and availability is confirmed during the evaluation.

What does it cost?

It depends on the modality and on your case. We evaluate each case and explain the conditions and costs.

References

1. Rienzi L et al. Oocyte, embryo and blastocyst cryopreservation in ART: systematic review and meta-analysis comparing slow-freezing versus vitrification to produce evidence for the development of global guidance. Hum Reprod Update. 2017;23(2):139-155. PMID: 27827818. DOI: 10.1093/humupd/dmw038
2. Cornet-Bartolomé D et al. Efficiency and efficacy of vitrification in 35 654 sibling oocytes from donation cycles. Hum Reprod. 2020;35(10):2262-2271. PMID: 32856058. DOI: 10.1093/humrep/deaa178
3. Rienzi L et al. Definition of a clinical strategy to enhance the efficacy, efficiency and safety of egg donation cycles with imported vitrified oocytes. Hum Reprod. 2020;35(4):785-795. PMID: 32240287. DOI: 10.1093/humrep/deaa009
4. Capelouto SM et al. When using donor oocytes, does embryo stage matter? An analysis of blastocyst versus cleavage stage embryo transfers using a cryopreserved donor oocyte bank. J Assist Reprod Genet. 2021;38(7):1777-1786. PMID: 33821428. DOI: 10.1007/s10815-021-02183-4
5. Allen CS et al. Tracking cryogenic tank failure from inception to critical warming: a site-specific analysis of sample-storage risk. J Assist Reprod Genet. 2026. PMID: 42850541. DOI: 10.1007/s10815-026-04051-5

This content is informational. It does not replace a consultation with a health professional, and laboratory rates are not individual probabilities of a live birth.