Take home message. Vitrification has become the cornerstone of modern IVF, combining precision in physics, chemistry, and biology to preserve the integrity and viability of gametes and embryos. Its ongoing evolution through AI, automation, and refined protocols ensures that cryopreservation remains both efficient and futureproof, safeguarding the potential for life.
Cryopreservation is a cornerstone of modern medically assisted reproduction and the science and practice behind this technique was dissected in detail at a three-day campus organised by SIGs Embryology and Fertility Preservation
The opening day focused on the fundamentals. George Liperis provided a comprehensive overview of the biophysical principles that underpin successful cryopreservation. His message was clear: to maintain the structural integrity, membrane function, and developmental competence of gametes and embryos after warming. “Cryopreservation,” Dr Liperis noted, “is an exercise in precision; a balance between physics, chemistry, and cellular biology.” The next presentation was delivered by Dr Gemma Arroyo Cardona who compared slow-freezing and vitrification, with the latter emerging as the superior approach for oocytes and embryos.
The genetic and epigenetic consequences of vitrification was highlighted by Dr Enrica Bianchi who reminded attendees that preserving viability must go hand in hand with safeguarding genomic stability. Catello Scarica’s lecture provided practical insights that make the difference between marginal and optimal results. He called for the timing after warming to be revaluated and noted the ongoing debate over equilibration exposure times. Evidence shows that shorter equilibration times are effective for blastocysts, although there are benefits of blastocyst collapse prior to vitrification.
Dr Ana Cobo presented new data on oocyte vitrification that show shortened vitrification and warming procedures can maintain success rates while improving workflow efficiency. She also discussed the growing role of artificial intelligence in predicting cryosurvival and implantation potential. Dr Llanos Medrano addressed the emerging field of sperm vitrification. Although standardised protocols remain elusive, promising results along with saving time are driving adoption of sperm freezing.
Day two moved toward refinement and regulation of cryopreservation. The question addressed by speakers was how best to apply, monitor, and future-proof the vitrification process in real-world IVF practice. Monica Marques opened the day with a pivotal question: when is the optimal moment to vitrify an embryo? Dr Marques reviewed outcomes across the developmental spectrum concluding that blastocyst vitrification remains the ‘gold standard’ because it is the most efficient and reliable stage for cryopreservation. Amy Barrie followed with a nuanced perspective on artificial intelligence in vitrification decision-making. Rather than imposing rigid thresholds for embryo or oocyte quality, Dr Barrie argued that AI’s strength lies in supporting clinical judgement. “AI should not decide if we freeze,” she noted, “but help us manage patients’ expectations.”
Stefano Canosa addressed one of the field’s persistent concerns: does long-term cryostorage compromise viability? Dr Canosa’s review of available data was reassuring. Oocytes and embryos remain remarkably stable for over a decade, with only moderate declines in live-birth rates and minimal transcriptomic changes.
Ana Cobo returned to discuss the emerging landscape of vitrification governance, a theme that merged laboratory science with data management. She highlighted the integration of AI and analytics for predictive maintenance and inventory optimisation, alongside rigorous risk assessment, KPI tracking, and adherence to international standards. In modern cryobanks, digital chain-of-custody systems using barcoding or radio frequency identification now ensure sample traceability, while real-time monitoring of liquid nitrogen levels and automated robotics are redefining efficiency and security. Automation is not about replacing embryologists.” she noted, but about safeguarding their precision.
The day concluded with two forward-looking talks and a practical session. Pasqualino Loi shared promising results from animal studies exploring dry preservation of male gametes, though oocytes remain a greater challenge. Dr Miguel Gallardo then presented the latest updates on rapid and universal vitrification and warming protocols, setting the stage for the campus’s interactive workshops. Participants embarked on hands-on vitrification practice, translating two days of theory into technique.
The closing day of the Zurich campus looked beyond gametes and embryos to the frontiers of gonadal and tissue cryopreservation. Andreas Schallmoser opened with the question: is it time to change our approach to gonadal tissue preservation? Drawing on multiple systematic reviews, Dr Schallmoser outlined the evolving evidence landscape. He concluded that vitrification and slow freezing should be viewed as complementary tools, with technique selection guided by laboratory expertise, tissue type, and patient context.
Next, Aurélie Feraille explored the vitrification of testicular tissue, still an experimental but rapidly advancing field. The technique avoids ice crystal formation and offers speed and cost advantages, particularly useful when working with few tissue fragments. However, its technical demands, potential cryoprotectant toxicity, and unproven fertility restoration in humans continue to limit clinical adoption.
One of the most practical and patient centred dilemmas in fertility preservation is when to choose oocyte vitrification over ovarian tissue cryopreservation. Claudia Massarotti explored this issue in a lecture which focused on the efficiency, limitations, and indications of each method. Dr Massarotti encouraged clinicians to tailor consultations around success rates, specific benefits and risks, and patient circumstances, ensuring informed, individualised decision-making.
The campus concluded with data presented by Ingrid Segers on pioneering work on oocyte vitrification in combination with in vitro maturation (IVM) for young women undergoing fertility preservation. While IVM-derived oocytes show lower maturation, developmental, and cryotolerance efficiency, Dr Segers’ told attendees: “Use IVM oocytes don’t waste them.”
By the close of the Zurich campus, an important message resonated: cryopreservation is not just a technique, but also the safeguard of potential life and the backbone of modern IVF. Its mastery demands unwavering attention, relentless training, and constant evolution to ensure every embryo and gamete has the best chance.
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