Blog4th June 2025
Next steps for the regulation of stem cell-based embryo models
Emma Cave
Stem cell-based embryo models (SCBEMs) – an umbrella term for a range of structures created from stem cells that replicate aspects of embryonic development – offer significant potential to advance our understanding of early human development, including pregnancy, miscarriage, developmental disorders and IVF.
As a relatively new field, SCBEM research currently falls outside of existing regulatory frameworks. Because, with further scientific advancements, some models may increasingly resemble embryos, they present important questions about their moral status and how they should be addressed within the law.
Last November, the Nuffield Council on Bioethics (NCOB) published recommendations for the future of SCBEM regulation, following an independent review of the ethical and governance issues overseen by an expert working group, which I chaired.
We concluded that a bespoke, proportionate and agile regulatory framework for SCBEMs should be developed in stages to support scientific progress, uphold ethical red lines and engender public trust.
Our proposals reflect a shared recognition in the sector of the need for more anticipatory and dynamic approaches so that governance can keep pace with innovation. When we published the proposals we knew that change could not happen overnight. But we stood ready to take our ideas to policy makers, and convene further discussions with researchers, funders, regulators and law makers that would be needed to take forward our recommendations.
A significant step in this journey was achieved earlier this month when the NCOB convened a policy roundtable attended by Health Minister Baroness Merron, Lord Willets, Chair of the UK Regulatory Innovation Office, regulators, funders and scientists.
Around the table, it was agreed that there is a need for a bespoke regulatory approach for SCBEMs, that builds on the UK’s historic success in developing world-leading regulatory frameworks for embryo research.
There was clear agreement that the process should start by embedding the recently developed UK Code of Practice on SCBEMs and the system of voluntary oversight, which would establish the groundwork for clear prohibitions and formal regulation in the medium term.
There was also broad support for initiating plans for the next steps we propose, which aim to establish formal regulation and clear legal prohibitions. In our report, we recommend building an iterative and proportionate model of oversight through a regulatory sandbox. This approach would help determine which SCBEMs should be regulated and on what basis, while also providing researchers with access to regulatory expertise as the science evolves.
One of the NCOB’s key recommendations is for legislation to distinguish SCBEMs from embryos. This is one aspect of the report that I have recently expanded upon in an open access article called Advocating Distinct Regulatory Paths for Embryos and Embryo-like Structures.
As biotechnology continues to advance, I believe that a distinction in law between embryos and SCBEMs is an essential component of a regulatory framework that reflects the complexities of both science and ethics, and allows for the responsible development of SCBEMs without overstepping moral boundaries.
At the policy roundtable there was support for distinguishing embryos and SCBEMs to ensure proportionate and targeted governance. One way this might be achieved is to amend the Human Fertilisation and Embryology Act 1990. Whether the Government will open up the Act within this Parliament is yet to be seen. But I was encouraged by the appetite in the room to explore opportunities to lay the groundwork for future regulation.
Participants acknowledged that designing regulatory frameworks that can keep pace with emerging and rapidly advancing technologies is a key challenge across the life sciences. Internationally, the UK has a reputation for excellence in the regulation of biosciences. With SCBEMs, we now face a critical choice – either confront this challenge proactively and support our world-leading life sciences sector, or risk falling behind. In this context, SCBEMs could serve as a valuable test case for developing anticipatory, agile regulatory approaches, with important lessons for other areas of bioscience.