Table 4 Main ethical, legal, regulatory, and policy issues and themes identified in journal articles

Potential benefits

Avoids practical and ethical concerns human embryo research raises

[9, 21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37, 47]

Reduces the reliance on animals for research

[22, 26, 30, 31, 35, 38, 39, 47]

Yields important knowledge to improve human health

[9, 21, 22, 24, 26, 30, 36, 40,41,42, 45, 46]

Eliminates the destruction of human embryos when induced pluripotent stem cells are used

[9, 29, 33]

Ethical significance or moral status concerns

Potential to create synthetic human life

[38, 49,50,51,52]

Are embryoids clones and, if so, what follows?

[21, 39, 45, 48, 52, 53, 61, 62, 65, 69]

Varying assessment of embryo moral status result in varying assessments of embryoid moral status

[18, 21, 28, 38, 41, 55, 61, 62, 77]

Assessment of moral status of embryos based on morally relevant features could guide assessment of embryoid moral status

[18, 30, 31, 37, 41, 44, 57, 63, 64]

Ethical significance of embryoids may vary based on their features

[9, 47, 49, 55]

Need to determine which features are morally relevant for assessing moral status

[49, 53, 54]

Level of embryoid complexity could determine moral status

[41, 49, 51, 54, 56,57,58,59,60]

Possibility of embryoids experiencing pain could determine moral status

[18, 36, 43, 44, 53, 57, 61]

Potential sentience in embryoids could determine moral status

[18, 36, 43, 57, 62]

Human organismic potential of embryoids determines moral status

[9, 18, 21, 23, 26, 35,36,37, 41, 49, 50, 52,53,54, 59,60,61,62,63,64,65,66]

What is the proper relationship between treatment of embryos and embryoids?

[9, 37, 41, 55, 57, 60, 61]

Embryoid research involves embryo destruction

[28, 68]

Permissible uses or applications

Embryoid research requires some limits

[34, 50, 51]

Should reproductive use should be banned?

[22, 37, 39, 47, 48, 52, 53, 60, 67, 69]

Should chimera creation should be banned?

[18, 52, 53]

Limit-setting may not be possible

[49]

Resolving questions regarding embryoids’ moral status may not resolve questions regarding permissible use

[41, 55, 62]

Are researcher intentions relevant to assessing permissibility of research?

[21, 35, 37, 41, 48, 57, 61]

Embryoid research could involve commercialization of human tissue

[40]

Regulatory and policy considerations

Questions regarding how embryoids fit within existing research guidelines, policies, and frameworks

[9, 18, 21, 23, 27, 28, 33, 34, 41, 44, 50,51,52, 55, 57, 60, 62, 64, 66, 67, 70,71,72]

Embryoids do not follow canonical embryogenesis

[9, 18, 27, 31, 34, 37, 47, 53, 60, 66, 67, 69, 70]

Implications for the 14-day limit for human embryo research

[18, 27, 41, 49, 54, 62, 64]

Inconsistent definitions of embryos and fetuses in existing regulations, policies, laws, and guidelines

[41, 45, 46, 55, 57, 60, 62, 64, 67]

Effect on stem cell research policy or oversight

[56, 67]

Should embryoid research be subject to separate regulations, guidelines, and oversight practices?

[18, 21, 26,27,28,29, 34, 44, 47, 52, 55, 67]

New policies and application of existing frameworks to embryoid research could undermine embryoid research

[39, 41, 70]

What should be the goals and priorities of embryoid research oversight and regulation?

[9, 18, 21, 41, 51, 59,60,61, 66]

Public trust in science or scientific institutions must be maintained

[43, 52, 55]

Transparency of science should be promoted

[21, 27, 41, 69]

Should the moral status of the embryoids determine policy adopted?

[53]

Should embryoid policy follow the precautionary principle?

[39]

Should different types of embryoids be subject to different regulations?

[41]

Who should develop any new guidelines, regulations, or policies and how?

[21, 27, 42, 52, 55, 57, 59, 60, 66]

Are public consultation, engagement, or deliberation necessary for developing guidelines?

[18, 21, 27, 36, 39, 42, 45, 46, 53, 60, 70]

International collaboration is important for developing guidelines

[53]

Ethical framework for embryoid research should be developed before regulatory framework

[18, 22, 39, 47, 54, 67]

Informed consent should be addressed in new guidelines

[43, 51, 64, 73]

Privacy should be addressed in new guidelines

[61, 73]

Benefit sharing should be addressed in new guidelines

[73]

New regulations, guidelines, or policies should be flexible to adapt to evolving science

[21, 23, 39, 41, 56, 59, 60, 67]