Research on human embryos is done on embryos not intended for implantation (surplus embryos). Research on embryos is used to study human development, develop treatments for diseases, and more. Using embryos in research stirs controversies stemming from various moral or religious views of the embryo. At their base is the fundamental question of whether the embryo is considered an entity whose moral status is equivalent to that of a living human, and as such bears the inalienable rights and interests to which any human is entitled, or whether it is a different kind of entity, lacking the moral status of a living human and as such not entitled to the protections and rights granted to humans. Those who hold the latter position tend to view the use of embryos in research as right and proper, with potential benefits for all humanity. In some respects, the bioethical discussion regarding embryo research parallels that regarding abortions. Opponents of abortion rights also tend to object to embryo research, while proponents of a women’s right to choose tend to support embryo research.
Due to the sensitivity of embryo research, the scientific community, in what is known as the “14-day rule,” has been instructed by ethical advisory committees not to perform experiments on embryos past the 14th day of their formation. There are several reasons for this cutoff point, some of them practical, such as the need to fix a defined limit after which the embryo takes on some human qualities and should not be experimented on, and some of them biological and related to the embryo’s developmental stages. The 15th day marks the appearance of the “primitive streak,” after which the embryo can no longer divide into twins (taken as an indicator of individuation), and the central nervous system begins to develop (taken to indicate the start of its transformation into a sentient being). Recently, with progress in the scientific capacity to grow human embryos in vitro up to day 13, a fierce debate has arisen within the scientific community regarding the appropriateness of the 14-day rule, with some calling for an extension of the threshold and others fearing a slippery slope leading to an excessive expansion of experimentation on embryos even at later developmental stages.
Selected ethical issues:
• Informed consent regarding the donation of embryos for research purposes.
• The moral status of human embryos not intended for implantation.
• Is the 14-day rule ethically sound in light of recent scientific developments in the field?