Sources of stem cells: ethical controversies and policy developments in the United States.

The bioethical controversy about public policy in the United States regarding human stem cell research, particularly with regard to several potential sources of stem cells, including aborted fetuses, unimplanted embryos following in vitro fertilization (IVF), and embryos created through IVF or cloning for research purposes is examined. On the one hand, the debate about the use of federal funds for this research was not resolved by President Bush's policy, announced in August 2001, because only a few cell lines are available under this restrictive policy. On the other hand, debate persists about whether the US should adopt a prohibitive, regulatory, or permissive policy toward the deliberate creation of embryos for biomedical research through somatic cell nuclear transfer. Although there is a wide consensus about the need to ban cloning-for-reproduction, there is deep division, reflected in the work of the President's Council on Bioethics, about a possible ban on cloning-for-biomedical research. The author concludes that ethical controversy will probably persist about both types of policy, and that the policy stalemate will probably also continue, because of fundamental disagreements about the moral status of the early embryo.