Reacción a "Reactions to the news on the creation of synthetic human embryos from stem cells"

Without a detailed preprint, or peer reviewed paper to accompany this press report, it is not possible to comment in detail on the scientific significance of this story. More generally, although it is very early days, synthetic models of human embryos based on stem cells have a lot of potential. They could provide fundamental insight into critical stages of human development. These are stages that have been very difficult to study and it’s a time when many pregnancies fail. Fresh insight might lead to a better understanding of the causes of miscarriages and the unique aspects of human development.

They also raise profound ethical and legal questions. Unlike human embryos arising from in vitro fertilisation (IVF), where there is an established legal framework, there are currently no clear regulations governing stem cell derived models of human embryos. There is an urgent need for regulations to provide a framework for the creation and use of stem cell derived models of human embryos.

On the one hand, models of human embryos made of stem cells might offer an ethical and more readily available alternative to the use of IVF derived human embryos. On the other hand, the closer stem cell derived models of human embryos mirror human embryos, the more important it is to have clear regulations and guidelines for how they are used. This itself raises challenges. How will comparisons be made given the difficulty of obtaining and studying human embryos at the appropriate stages.

It is important that research and researchers in this area proceed cautiously, carefully and transparently. The danger is that missteps or unjustified claims will have a chilling effect on the public and policymakers, this would be a major setback for the field.