Human embryo research is a controversial topic that often pits the necessity of biomedical investigation against the moral commitment to protect early human life. A new series of research papers from Rice University’s Baker Institute for Public Policy is discussing human embryos and the related ethical, policy and scientific issues that arise during the research process.
The first paper, “Politics and Policies Guiding Human Embryo Research in the United States,” by Kirstin Matthews, a fellow in science and technology policy in the Center for Health and Biosciences at the Baker Institute, and former research assistant Erin Yang reviews the history of federal, state and private policies impacting this research. It also examines the possibility and the potential impact of changes to those policies.
“Human embryo research … forces us to consider who counts as a person, what it means to be a human being, what rights and interests are accorded to human beings at various stages of development, and what may be done to humans at various stages of life under different circumstances,” the authors wrote.
The research has also been linked to public debates and disagreements, especially in the U.S., related to abortion, the authors said.
“Finally, this area of research requires us to determine the limits we should place on scientific research and knowledge,” the authors wrote. “Is any human embryo research that advances knowledge acceptable? If not, what limits should be imposed, and who should set them?”
The term “embryo” is widely accepted as the mass of cells in the earliest stages of development into a new organism, the authors said. Scientists define the human embryonic stage as the time from fertilization to the eighth week of gestation (56 days after conception), when it becomes known as a fetus and starts to develop more advanced physical and neurosensory features. U.S. federal law does not define the term “embryo”; instead, it defines a fetus as the entity from the implantation stage (which scientists define as 7–14 days after conception) to delivery. For their paper, the authors used the term “embryo” to describe the time of development from the first 56 days after conception.
Early human embryo research led to in vitro fertilization (IVF), which revolutionized medical treatments for infertility, the authors said. Scientists conducted decades of research to develop IVF techniques before the procedure was first successfully performed in 1978 by British scientists Robert Edwards and Patrick Steptoe.
Human embryo research received substantial media attention when such research was linked to the emerging field of regenerative medicine, the authors said. In 1998, scientists — many of whom were from the U.S. — reported culturing human embryonic stem cells (hESCs) for the first time.
“hESCs, obtained from 5- to 6-day-old embryos, offered scientists the possibility of creating almost any cell or tissue in the human body, providing a new tool to study early human development and different disease states with the goal of eventually developing treatments to replace diseased or injured cells or tissues,” the authors wrote. “However, this research and the isolation of hESCs required the destruction of embryos.”
From 1949’s Nuremberg Code, which described ethical principles that should govern human research, to the U.S. Department of Health and Human Service’s 2017 draft of a strategic plan that adds “beginning at conception” to its mission statement, human embryo research has been impacted by various ethical commissions, regulations, legislation, policy developments and scientific achievements.
Even before IVF, discussions were underway in the U.S. over whether research that uses embryos or results in their destruction is ever permissible and, if so, under what circumstances, the authors said.
“Over the past four decades, policies have been proposed by national bioethics commissions, but little has been achieved in terms of a legislative solution,” the authors wrote. “Instead, most human embryo research is guided by an unofficial limit allowing research only until the 14th day of development, which dates back to a 1979 U.S. Department of Health, Education and Welfare report on IVF. This end date is not specified in any law and is irrelevant to federally funded research, since no human embryo research is funded by the federal government. But the limit is accepted by nongovernmental organizations, especially professional societies that oversee scientists and doctors who would participate in such research.”
Scientists’ ability to study early human embryo development in vitro has, until recently, been limited to the time the implantation stage begins (between days 5 and 7), which is also when an IVF egg would be implanted, the authors said. However, in May 2016, two research groups (one from the U.S. and the other from the U.K.) reported culturing human embryos in vitro up to the 14-day limit.
“After these groups had to halt their experiments because of the 14-day guideline, some scientists and ethicists called for a reevaluation of the decades-old rule,” the authors wrote. “Proponents of extending the guideline to later time points cite the therapeutic possibilities that could arise with more research on early development. But other scholars noted that the guideline was a hard-won compromise and urged that it not be lifted.”
The authors concluded, “While science and research continue to progress, it is the role of policy to guide this research. As the Nuremberg Code and the Common Rule did for broader human subjects research, so the 14-day rule does for human embryo research. Beyond the policies that can be implemented, we should also address what should be done from a moral standpoint. These questions are addressed in the companion reports that will follow, which assess the scientific merit of expanded human embryo research — i.e., what can be done — and ethical questions associated with altering the 14-day guideline for human embryo research in the United States — i.e., what ought to be done.”
Source: Rice University