A recent opinion article published in Nature Cell Biology underscores advancements in stem cell-derived embryo models that have enabled research in human embryology. For this progress to continue, rigorous experimentation is required along with a robust ethical framework and effective public communication to achieve societal support.
Human embryos have profound ethical significance which, demands careful consideration. Models developed from stem cells, mimicking embryos, offer insights into developmental principles and stimulate/promote medical progress. Misrepresentation of these models risks distorting research and misleading the public, undermining trust in science.
The authors of the opinion piece are leading experts from around the world and they describe the historic public misperceptions that have hindered progress, the new avenues of human embryo research and the necessity of defining embryo models for scientists and public alike (1). Mistrust in human embryology, stemming from ancient beliefs and modern myths, has hindered scientific progress in the past. The field of medical assisted reproduction faced severe criticism before it became widely accepted, with 4% of all births in Europe resulting from IVF. In a world where moral values are constantly changing, stem cell biologists and embryologists prioritise ethical paths towards understanding human development and addressing medical challenges.
As the authors point out, knowledge of early human embryogenesis originated mostly from donated surplus embryos from patients completing their families through IVF treatment. Nonetheless, research using these embryos does not usually exceed 14 days from fertilisation, if not earlier for some countries. Historically, stem cell research comprised of mouse and human stem cells organising into structures resembling embryos. While these models have limitations and do not form viable organisms, their practicality is an added benefit that can facilitate research, especially in countries where embryo research is restricted. Even though the ability of embryo models to mimic embryogenesis is unknown, they have the potential to reveal important genes, molecules, and cells at play. Rivron et al., indicate that embryo models can fill an important knowledge gap and hold potential for understanding developmental processes, battling infertility and pregnancy loss, as well as revealing the origin of birth defects.
Advancements in embryo models require careful consideration of the ethical framework and governance in regard to their legal status, their use in reproduction and their realistic contribution to science and medicine. The authors suggest that a holistic approach is required from a multidisciplinary team of biologists, ethicists, philosophers, and legal scholars. Discussions among experts and the public have shaped international guidelines for using embryo models responsibly. Recommendations emphasize caution on the use of complete models. Research is only permitted following ethical approval and transfer into a uterus is not permitted. The authors emphasise that use of human embryo models is not always justified from a scientific and ethical perspective, especially when alternatives such as gastruloids, assembloids and organoids are available. These recommendations steer ongoing discussions by national ethics committees to align with societal values as well as from international funding agencies and scientific societies, such as the International Society for Stem Cell Research (ISSCR) and ESHRE. Basic ethical principles have existed since the second half of the 20th century, but political and religious beliefs can hinder research. This is demonstrated by the previous ban of federal funding in the US for human embryonic stem cell research and the existing ban in Germany on using surplus patient embryos.
The challenges in science dissemination are also a major point raised by the authors. The ISSCR fundamental principles state that scientists have a duty to communicate their results in a trustworthy, accessible, and timely manner to maintain public confidence (2). International societies such as ISSCR and ESHRE, local committees such as the Cambridge Reproduction Initiative, and information outlets for journalists such as the Science Media Centre in the UK, Spain, and Germany all aim to provide accurate, diverse, and measured opinions.
Effective communication of scientific results to the public is vital. Transparency, accessibility, and verifiability of data are crucial to maintain public trust. However, premature dissemination, lack of scrutiny, and sensationalism, risk the misinterpretation of information. As the authors state, use of specific language such as ‘synthetic embryos’ by the press gives the impression that these are embryos created from scratch for use in reproduction. Scientists, the media, and press offices play key roles in accurate and measured information dissemination. Correct language, like 'stem cell-based embryo models’, is crucial for accurate communication and to avoid misconceptions. Moreover, Rivron et al., state that since these models present unknowns regarding their status and contributions to medicine, ethical evaluation should be a continuous exercise.
On this basis, the authors summarise that progress in human embryology requires steady advancement, devoid of sensationalism. Regular re-evaluation of ethical considerations and governance policies is crucial. Scientists engaging with the public can enhance accurate information dissemination, building a stronger foundation for impactful human embryology.
1. Rivron, N.C., Martinez-Arias, A., Sermon, K. et al. Changing the public perception of human embryology. Nat Cell Biol 25, 1717–1719 (2023). https://doi.org/10.1038/s41556-023-01289-4
2. International Society for Stem Cell Research. Guidelines for Stem Cell Research and Clinical Translation. International Society for Stem Cell Research. https://www.isscr.org/guidelines