Scientists say increasing limit from 14 days will give greater insight into congenital conditions
Scientists will make a controversial call this week to extend the current 14-day limit for carrying out experiments on human embryos to 28 days. The move follows recent breakthroughs that have allowed researchers to double the time embryos can be kept alive in the laboratory.
By extending the current research period, major insights into congenital conditions, heart disease and some cancers could be gained, they will argue at a conference in London on Wednesday.
But the move will be viewed as being highly provocative by opponents of embryo research and will be vigorously opposed by many religious leaders and politicians. Previous opposition to embryo experiments has been on the grounds that such research represents a slippery slope that will culminate in unrestricted research being carried out on living embryos.
Opposition to the extension bid is not restricted to the religious right. Among those calling for the current 14-day limit to be maintained is the British philosopher Mary Warnock. In order to allow some key research to go ahead but within tightly controlled parameters, Warnock originally proposed the limit in her commission’s 1984 report on fertilisation research.
This later formed the cornerstone of the 1990 Human Fertilisation and Embryology Act which has permitted scientists to create human embryos, using in vitro fertilisation technology, for research – but only to a maximum period of 14 days.
“We should note that every time the law about embryo research has been changed or amended the opposition has rallied its forces, and I think it would do so again if we try to get the 14-day rule extended,” Warnock told the Observer. “The risk is that all the progress we have made since 1990 would be lost. I think we should stick to the 14-day limit.”
The proposal to extend the period will be made at the Progress Educational Trust by leading fertility experts Professor Robin Lovell-Badge, of the Francis Crick Institute in London, and IVF expert Professor Simon Fishel, head of the CARE Fertility Group. “The benefits for medical research would be enormous,” 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.”
Lovell-Badge agreed. During the period from around seven days to 28 days after conception all sorts of critically important stages in human development take place, he said.
“In particular there is the process known as gastrulation, when the body plan is laid down and the three main tissue layers – the ectoderm, mesoderm and endoderm – are formed as the biological foundations for the specialised tissues of the nervous system, muscle and blood, and lungs and intestines.
“We know very little about that time in human development. Indeed, we know far more about that stage in other animals. However, by extending the time we can keep human embryos in the laboratory to 28 days we have a chance to tackle this critically important early stage in human development.”
Lovell-Badge added that there would be no need to make further increases in the experimentation limit beyond 28 days. “We have other sources of embryonic cells – from material left over from ectopic pregnancies, for example – that already provide information about these 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.