The ethic of stem cell-based embryo models

Blastoids are scientific models that are used in the lab to answer biological and biomedical questions. Because they are formed solely from stem cells, they alleviate the use of embryos, while opening unique possibilities (high-throughput screens, genetic engineering) that are the basis of biomedical discoveries. Thus, blastoids allow investigating in the lab previously inaccessible questions, while being an ethical alternatives to the use of embryos for research.


Blastoids are not considered legally equivalent to blastocysts, in part due to their incapacity to develop in utero. But they also question the current ethical status quo. What should their legal and ethical status be in the future as they are refined? Do the probable insights they provide outweigh possible ethical concerns?

We are contributing to an international discussion involving ethicists, philosophers, lawyers, and international scientific societies with the aim of guiding this research. Our goal is to propose a clear framework for stem cell-based embryo models. For example, we advise regulators to encourage their use as in vitro scientific models while banning their use for reproductive purposes. This discussion has led to an updating of the ethical guidelines of the International Society for Stem Cell Research (2021) including a framework for research making use of embryo models.


We stated our propositions in several publications that serve as a basis for further discussions.

ISSCR Guidelines for Stem Cell Research and Clinical Translation: The 2021 update.

Lovell-Badge R, Anthony E, Barker RA, Bubela T, Brivanlou AH, Carpenter M, Charo RA, Clark A, Clayton E, Cong Y, Daley GQ, Fu J, Fujita M, Greenfield A, Goldman SA, Hill L, Hyun I, Isasi R, Kahn J, Kato K, Kim JS, Kimmelman J, Knoblich JA, Mathews D, Montserrat N, Mosher J, Munsie M, Nakauchi H, Naldini L, Naughton G, Niakan K, Ogbogu U, Pedersen R, Rivron N, Rooke H, Rossant J, Round J, Saitou M, Sipp D, Steffann J, Sugarman J, Surani A, Takahashi J, Tang F, Turner L, Zettler PJ, Zhai X. Stem Cell Reports. 2021 Jun 8;16(6):1398-1408. doi: 10.1016/j.stemcr.2021.05.012. Epub 2021 May 27. PMID: 34048692

Human embryo research, stem cell-derived embryo models and in vitro gametogenesis: Considerations leading to the revised ISSCR guidelines.

Clark AT, Brivanlou A, Fu J, Kato K, Mathews D, Niakan KK, Rivron N, Saitou M, Surani A, Tang F, Rossant J. Stem Cell Reports. 2021 Jun 8;16(6):1416-1424. doi: 10.1016/j.stemcr.2021.05.008. Epub 2021 May 27. PMID: 34048690


Toward Guidelines for Research on Human Embryo Models Formed From Stem Cells.

Stem Cell Reports. 2020 Feb 11;14(2):169-174. doi: 10.1016/j.stemcr.2019.12.008. Insoo Hyun, Megan Munsie, Martin F Pera, Nicolas C Rivron, Janet Rossant

Debate ethics of embryo models from stem cells.

Rivron N, Pera M, Rossant J, Martinez Arias A, Zernicka-Goetz M, Fu J, van den Brink S, Bredenoord A, Dondorp W, de Wert G, Hyun I, Munsie M, Isasi R. Nature. 2018 Dec;564(7735):183-185. doi: 10.1038/d41586-018-07663-9.