In 2018, researchers at the University of Edinburgh, led by Professor Evelyn Telfer, achieved something no one had managed before: growing a human egg in the lab from its earliest stage all the way to full maturity. The work built on three decades of research and was seen as a potential path towards protecting the fertility of girls diagnosed with cancer before puberty, a group with very limited options today.
How the Process Works
Human eggs mature naturally after puberty, discarding roughly half their genetic material into a structure called a polar body as part of that process. Telfer’s team replicated key stages of this maturation outside the body, using small samples of donated ovarian tissue, carefully formulated culture mediums, and growth-supporting proteins and hormones, with tightly controlled temperature and oxygen conditions.
The early results were promising but far from a finished technique. Only around one in ten eggs grown this way reached full maturity, and the resulting polar bodies were often larger than normal a difference researchers flagged as worth investigating further, though not necessarily a sign the eggs themselves were unhealthy. Because fertilising the eggs required separate regulatory approval that hadn’t yet been granted, their viability couldn’t be tested at the time.
Where the Research Stands Now
More recent reporting shows the team has continued refining the technique in the years since. As of 2025, Professor Telfer’s group was preparing to trial the method in sheep as a next step before human trials, with the team estimating human trials could begin within five to ten years, and broader clinical use realistically much further out. This is a useful reminder that breakthroughs like this one typically move from lab result to available treatment over the course of decades, not years.
What This Could Mean for Fertility Preservation
If the technique is eventually proven safe and effective, its most significant impact would likely be for girls facing cancer treatment before puberty. Adults facing fertility-threatening treatment can already freeze eggs or embryos, but this isn’t possible for prepubescent girls, whose eggs haven’t yet matured. Currently, the only option available to this group is freezing ovarian tissue for possible reimplantation later a more invasive approach with its own limitations. Lab-grown eggs could, in time, offer a lower-risk alternative.
It’s important to be clear-eyed about timelines, though. For anyone facing a fertility decision today whether due to age, medical treatment, or another circumstance options like egg freezing, embryo freezing, and donor egg treatment remain the established, available paths, while techniques like lab-grown eggs continue to be researched.
Could This Eventually Help Beyond Cancer Patients?
Most of the research focus so far has centred on fertility preservation for young cancer patients, but the underlying science understanding exactly how an egg matures from its earliest stage to one capable of fertilisation has broader relevance too. A deeper understanding of healthy oocyte development could, in theory, eventually inform research into age-related egg quality decline more generally, which is one of the central challenges in fertility medicine. That said, this remains a research direction rather than a near-term treatment, and researchers themselves have been consistently cautious about overstating how soon any of this could reach patients.
Frequently Asked Questions
Is lab-grown egg technology available as a treatment yet?
No. It remains an active area of research, currently moving from human tissue studies towards animal trials, with human trials realistically still years away and broader clinical availability further out still.
What options exist today for preserving fertility before cancer treatment?
For patients who have already gone through puberty, egg or embryo freezing before treatment begins is the most established option. For prepubescent girls, ovarian tissue freezing with potential future reimplantation is currently the primary option available, though it carries its own risks and limitations.
If lab-grown eggs aren’t an option yet, what can I do now?
If you’re facing a fertility decision today, it’s worth discussing your specific circumstances with a fertility specialist, who can talk through currently available options such as egg freezing, embryo freezing, or donor eggs, depending on what applies to your situation.
If you’d like to discuss which of today’s options might suit your situation, you can get in touch with our team.
