The Ethics and laws around growing Human embryo’s and their status have been a contentious topic since the first experiments deriving stem cells in 1981. And it is an area in which the law leaves areas unclear given recent advancements in synthetic embryos. Currently in the UK embryos are not allowed to be grown outside of the womb for more than 14 days, the reasoning behind this being that it is the best guess for the last point in which an individual, instead of multiple people, could develop from a single embryo. Given these rules, and the understanding that Embryos cannot grow into foetuses outside of the womb, in many countries embryos are not legally considered people. This idea has been challenged recently in the US, where the Alabama supreme court ruled that frozen embryos used in IVF are considered children.

What are synthetic embryos

Embryos are the initial stage of development of multicellular life, starting as the blastocyst (formed from the fertilisation of the egg cell by a sperm cell) implants onto the walls of the uterus. For most of history this was the only way to form an embryo, until 2022 when a team at the Weizmann Institute in Israel manipulated mouse stem cells, which then grew into embryo like structures. This work has been continued and since then scientists at the University of Cambridge have created synthetic mouse embryos that have formed with a brain, nervous system and beating heart.

Ethics of using synthetic embryos

Research using synthetic embryos has many touted benefits, many pregnancies fail in the first weeks when the cells that will become the embryo, placenta and yolk sac differentiate, and the hope is synthetic embryos will allow further research into this area, where current research with human embryos is limited due to the 14 day rule. It also allows research in understanding the development of the brain, as this starts developing later than 14 days and cannot be examined closely inside the womb. The rational behind these synthetic embryos being developed for longer periods of time is that they are models of the human embryo, and would not be able to develop into the foetal stage.

There are many questions on the morality of creating synthetic embryos. If the synthetic embryo is recognised as children, much alike the case in the Alabama Supreme court, then the embryo could be seen as a clone of the person who donated the stem cells, Importantly Human cloning is banned in most countries around the world and thus would make the development of these embryos illegal.

Currently the only limit to this research in the UK is that it is illegal to implant synthetic embryos into a human womb.  This leaves a wide range of possibilities for research, and questions are being asked about what stage these embryos can be grown to before they are seen as alive. This question has yet to be agreed on regarding the development of natural foetus’ and so likely will be a long time before it is answered.

Links

Epstien, K. (2024) Alabama IVF ruling: What does it mean for fertility patients?, BBC News. Available at: https://www.bbc.co.uk/news/world-us-canada-68366337 (Accessed: 06 March 2024).

Collins, S. (2022) ‘Synthetic’ embryo with brain and beating heart grown from stem cells by Cambridge scientists, University of Cambridge. Available at: https://www.cam.ac.uk/stories/model-embryo-from-stem-cells (Accessed: 06 March 2024).

Villalba, A., Rueda, J. and de Miguel Beriain, Í. (2023) ‘Synthetic embryos: A new venue in ethical research’, Reproduction, 165(4). doi:10.1530/rep-22-0416.