Why the UK should extend the 14-day rule to 28 days

It seems that lately there has been growing discussion about how the UK's Human Fertilisation and Embryology Act (1990 as amended) may eventually be updated or replaced with new legislation that better reflects the changing landscape and needs of medicine, science and society. One area of the Act that would be a good candidate for review would be the current regulations for research on embryos.

Currently, the Act follows what is known as the '14-day rule', which as the name suggests, allows licensed research on embryos up to the equivalent of the 14th day of development. However, as I have argued in an opinion piece with Professor Annelien Bredenoord in EMBO Molecular Medicine, we now know more about the science of embryo development compared to over 30 years ago when the Act came into force, and it now makes ethical and scientific sense to extend the permissible window for embryo research to 28 days (ie, the '28-day rule'). In fact, the International Society for Stem Cell Research (ISSCR) has relaxed its recommendation that the 14-day rule be followed. In what follows, I briefly consider a few of the reasons why extending the 14-day rule would be beneficial, a few of the areas in need of special attention in future regulation on embryo research, and why education is a key element in any future efforts to extend the time limit on embryo research.

To begin, there are important scientific benefits to extending the 14-day rule to 28 days, for embryo research in the UK. It often comes as a surprise to many that our scientific knowledge of human embryo development between the 14th and 28th day has been limited due to both regulatory and, up until recently, scientific obstacles to studying the embryo during this period. The reason that 28 days is a reasonable new time limit for research is that we already have good scientific evidence on embryo development beyond this 28-day point.

If opening the so-called 'black box' of embryo development beyond the 14th day became possible, this would potentially enable scientists to gain a better understanding of the formation of primitive tissues, the development of the nervous system and early organ development. It is also possible that scientists could gain a better understanding of why some pregnancies end in miscarriage or stillbirth and some don't, and why some birth defects occur. In short, a better understanding of embryo development has the potential to benefit parents, their future offspring, and avoid what may actually be unnecessary suffering (which we currently endure in the absence of better knowledge of how to avoid or treat it). Maintaining the status quo of the 14-day rule is therefore by no means a morally neutral option.

Any revision of and extension to the UK's 14-day rule should also pay close attention to a few key considerations that I'll touch on here. It is now the case that cutting-edge research is being carried out by scientists to derive gametes and embryos in vitro from stem cells. Given these gametes or embryos may not be derived from cells taken from the testes or ovaries, how should any such novel in vitro stem cell-derived gametes or embryos be regulated in research and reproduction going forward? Future regulation needs to carefully review what should constitute a 'permitted' gamete or embryo, and provide good scientific and ethical reasons for the regulation that is ultimately chosen.

Similarly, special consideration should also be given to how the law should regulate research on synthetic human entities with embryo-like features (SHEEFs) and some forms of organoids (ie, miniature 3D tissue models of organs). Each of these technologies has important implications for future medical treatments and research, and revisions are needed to embryo research regulation in order for these technologies to be explored safely and effectively.

If the UK's embryo research regulation is going to get the update and extension it needs, then a fundamental part of this process will be educating all stakeholders. Embryo development is a complicated area of science and there are many misconceptions about the features of embryos at different times of development and also the ethical arguments surrounding the use of embryos in research. For instance, many people, ranging from members of the public to academics working in the field of reproduction, still believe that it might be possible for embryos to feel pain between the 14th and 28th days of development, despite no neural connections existing in the embryo during this period.

Similarly, often the presence of the primitive streak (the point at which gastrulation begins and embryo twinning can no longer occur) has historically been misunderstood to be an indication that the embryo can feel pain, and this erroneous claim has occasionally been deployed in ethical and legal debates, as explained by Dr Duncan Wilson in The Making of British Bioethics.

Additionally, it is not uncommon for scientific debates surrounding embryo research to treat any or all moral arguments that are against or in favour of embryo research as being of equal importance, valid or sound.

Last but not least, the public must be educated about the real benefits and risks of embryo research and how extending the embryo research time limit could impact the future treatments, technologies, and knowledge that are available. This will take time, and any consultation process on regulation change should factor in enough time to engage the public with educational materials and resources so that any views requested from them are as informed as possible.

While revising and extending UK regulation for embryo research is an important next step in keeping up with scientific progress and clinical need, it is also a fragile process that requires careful preparation and the provision of an open consultative process that allows all voices and views to be shared.