Bioethics Blogs

Pushing the 14-day limit on human embryo research

Françoise Baylis calls for a better alignment of the science and ethics of human embryo research.


Scientific and political elites have long known the day would come when scientists would challenge the 14-day limit on human embryo research. Indeed, Sir Robert Edwards, one of the pioneers of IVF, suggested that the limit should be 21 days. And, in Canada, as far back as 1995, the government-sponsored “Discussion Group on Embryo Research” (which endorsed the internationally accepted norm of 14 days) also noted that “this limit should be subject to modification should there be new and compelling ethical or scientific justification to do so.”

This week, two research teams – one at Rockefeller University in the United States and the other at the University of Cambridge in the United Kingdom – have reported research involving human embryos kept in vitro for 12-14 days. Prior to this there were no reports of human embryos cultured in vitro beyond nine days.  This scientific breakthrough has prompted a call to revisit the 14-day limit on human embryo research. But is this technological prowess sufficient to warrant a change in law or policy?  That is, do we have “new and compelling ethical or scientific justification” to change the 14-day rule?

The 14-day rule was initially recommended by the Ethics Advisory Board of the United States Department of Health, Education, and Welfare. Its 1979 report in Support of Research Involving Human In Vitro Fertilization and Embryo Transfer stipulated that human embryos should not “be sustained in vitro beyond the stage normally associated with the completion of implantation (14 days after fertilization).”  The proponents of this limit argued that individuality was a determinant of moral status, and that individuality could only be established once implantation was complete.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.