New Human Embryo Models Require New Guidelines for Their Ethical Use in Research

July 3, 2023

When the current guidelines regarding the ethical use of human embryos in research were developed, scientists couldn’t imagine the possibility of stem cell-derived embryo models (SEMs) that recapitulate different stages of embryonic development. But now that SEMs exist, new regulations and policies that permit their ethically appropriate research use need to be developed according to the paper, “Human Stem Cell-derived Embryo Models: Towards Ethically Appropriate Regulations and Policies,” published today in Cell Stem Cell.

“The similarity of the stem cell-derived embryos to natural embryos raise many ethical questions. It’s not obvious if they should be considered solely as lab models, or as akin to actual embryos in moral status and legal provisions,” said the paper’s co-author Dr. Jeremy Sugarman of the Johns Hopkins Berman Institute of Bioethics. “Ethical issues loom over rapid advances in embryo modeling and we need to take action now to ensure ethically appropriate scientific ingenuity and process.”

 Sugarman outlined a number of broad areas with open questions pertaining to the use of SEMs in research, including:


  • How similar are SEMs to natural embryos? Can they develop a brain, or be implanted?


  • Do SEMs have moral status? Is it ethically appropriate to derive SEMs? To use them for research?


  • Do existing laws, policies and legal definitions apply to SEMs? Are existing laws sufficient to regulate them? Do existing oversight bodies have authority over SEM research? Are new laws needed?

Sugarman points out that the 14-day rule that forms the cornerstone of many current embryo research policies and regulations, not permitting their use 14 days after fertilization, is complicated in regard to SEMs since no fertilization event exists from which the counting of days can begin.

“Existing legal definitions of ‘human embryos’ should be adapted to clarify which current provisions apply to SEMs and appropriate oversight must be established for this research,” said Dr. Sugarman.

“It is crucial that the scientific community continues to promote widespread discussion of experimental possibilities in order to inform the public about latest advances in this field, apprehend societal concerns, and propose specific guides for researchers. This kind of leadership is all the more needed as research progress dares human imagination, confounds ethical intuition and challenges the application of existing policies.”