Though these are exciting strides toward the future, however, the work also raises serious ethical and legal issues as the lab-grown entities are created outside current legislation in the UK and most other countries.

It still needs to be determined whether these structures have the potential to mature beyond the earliest stages of development.

But we are witnessing how rapidly the science in this field has outgrown the law, and scientists are already moving to draw up voluntary guidelines to govern work on synthetic embryos.