Subscribe to the BioNews newsletter for free

Advanced Search

Search for

Like the Progress Educational Trust on Facebook



Proposal to extend 14-day limit on human embryo research

05 December 2016

By Annabel Slater

Appeared in BioNews 880

An extension to the 14-day human embryo research rule will be proposed at the Progress Educational Trust (PET) conference 'Rethinking the Ethics of Embryo Research: Genome Editing, 14 Days and Beyond' on 7 December.

Until now, human embryo research has been restricted in the UK under the Human Fertilisation and Embryology Act 1990, which only permits research on human embryos up to 14 days old. However, until recently no scientists were able to maintain live embryos for longer than seven days.

Earlier this year, Cambridge researchers led by Professor Magdalena Zernicka-Goetz proved they could keep embryos alive for up to 13 days (see BioNews 850). This has opened up possibilities for research on embryos beyond 14 days, which scientists argue could lead to critical insights into human development.

Dr Simon Fishel, founder of CARE Fertility, will support a proposal to extend the limit up to 28 days at the PET conference.

'The benefits for medical research would be enormous,' Dr Fishel told the Observer. 'Certain tumours, developmental abnormalities, miscarriage – there is a whole raft of issues in medical science that we could start to understand if we could carry out research on embryos that are up to 28 days old.'

But critics warn that an extension could be regarded as a 'slippery slope' to unrestricted embryo testing, provoking a backlash that would negatively impact embryo research in the UK. These critics include the philosopher Baroness Mary Warnock, a patron of the Progress Educational Trust (which publishes BioNews), who originally advised the UK government to adopt the 14-day limit in a 1984 report which was key to the 1990 Act.

'We should note that every time the law about embryo research has been changed or amended the opposition has rallied its forces, and it would do so again if we try to get the 14-day rule extended,' Baroness Warnock, who will also be speaking at the conference, told the Observer. 'The risk is that all the progress we have made since 1990 would be lost.'

At the time, this limit was recommended as appropriate 'in order to allay public anxiety'. Scientists believe that 14 days is the point at which the 'primitive streak' begins to form, which is the precursor of the central nervous system. Beyond this point the embryo is also unable to split to form twins.

Speaking to the Observer, Baroness Warnock warned: 'If we raise the limit, objectors could argue that the 14-day rule has remained intact simply because no researcher had the technique to keep an embryo alive for so long, and that now one has been discovered the rush down the slippery slope will follow.'

Yet Dr Fishel disagrees. 'Everything will continue to be regulated and assessed on a case-by-case basis. Nothing worse can come from it, all this talk of slippery slopes is just scaremongering.'

Professor Robin Lovell-Badge, group leader in stem cell biology and developmental genetics at the Francis Crick Institute, London, told the Observer that other sources of embryonic cells, including material leftover from ectopic pregnancies, could provide information about later stages of human development.

'The move to 28 days would be the last change we would need to make in controlling embryo research,' he said.

'Rethinking the Ethics of Embryo Research: Genome Editing, 14 Days and Beyond' is taking place in London on Wednesday 7 December 2017. Click here for full details, and email with any queries.


23 January 2017 - by Anna Leida 
A recent YouGov poll has shown that almost half of the general public is in favour of legalising research on embryos up to 28 days old...
23 January 2017 - by Rachel Siden 
In this podcast, Professor Magdalena Zernicka-Goetz and Sarah Norcross discuss the current UK ban on researching human embryos in the lab for longer than 14 days...
09 January 2017 - by Baroness Mary Warnock 
As the Progress Educational Trust's Patron, Baroness Mary Warnock, is made a Companion of Honour in the New Year Honours List 2017, she offers her thoughts on whether the 14-day limit on human embryo research (which she originally proposed in 1984) should be extended...
09 January 2017 - by Dr Valerie Shaikly 
The second session of the Progress Educational Trust's annual conference 'Rethinking the Ethics of Embryo Research: Genome Editing, 14 Days and Beyond', looked at new embryo images that have potential to challenge the 14-day rule and discussed the potential benefits of extending the rule beyond the existing time limit...
19 December 2016 - by Giulia Cavaliere 
It's not enough to just talk about the benefits of extending the 14-day rule, we must also consider the views of those who believe that human embyros are persons...

16 May 2016 - by Dr Helen O'Neill 
Species-specific differences in terms of developmental timing and molecular expression patterns have restricted our true understanding of early human development...
09 May 2016 - by Julian Hitchcock 
The advances of Magdalena Zernicka-Goetz, the opportunities to undertake valuable medical research and our changed sense of values all demand that we reappraise the 14-day limit...
09 May 2016 - by Julianna Photopoulos 
Scientists from the UK and US have grown human embryos in the lab for 13 days after fertilisation – the longest ever recorded. This is beyond the stage when embryos would normally implant in the womb, but just before the 14-day legal limit in the UK...
01 February 2016 - by Dr Kirsty Horsey and Dr Sue Avery 
Last November, we accepted an invitation to have coffee and a chat with Mary Warnock. We had no real brief – we just looked forward to a tour through her life and her thoughts on what she had done for the world of assisted reproduction...

Be the first to have your say.

You need to or  to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions

- click here to enquire about using this story.

Published by the Progress Educational Trust


Public Conference
8 December 2017

Speakers include

Professor Azim Surani

Professor Magdalena Zernicka-Goetz

Professor Robin Lovell-Badge

Sally Cheshire

Professor Guido Pennings

Katherine Littler

Professor Allan Pacey

Dr Sue Avery

Professor Richard Anderson

Dr Elizabeth Garner

Dr Andy Greenfield

Dr Anna Smajdor

Dr Henry Malter

Vivienne Parry

Dr Helen O'Neill

Dr César Palacios-González

Philippa Taylor

Fiona Fox

Sarah Norcross

Sandy Starr


Good Fundraising Code

Become a Friend of PET HERE and give the Progress Educational Trust a regular donation