Officials from the US National Institutes of Health (NIH; Bethesda, MD) late in August issued guidelines for human pluripotent stem cell research featuring special review procedures that apply to federally, but not privately, funded studies in this subject area. Although intended mainly to address ethical concerns about obtaining and using starting materials, the guidelines appear unlikely to quell the continuing debate in Congress and elsewhere surrounding such research, which is embroiled in the broader dispute over abortions that has often proved pivotal in US national politics.

A principal source of pluripotent stem cells is discarded human embryos, on which federally sponsored research is prohibited. Congress renews this prohibition year after year through language inserted into NIH appropriation bills. Although attorneys in the Department of Health and Human Services have said that this prohibition does not encompass stem cell research as such, the guidelines are meant, in part, to head off any efforts to broaden the prohibition. The guidelines specify that no federal funds may be spent directly on creating human embryos as sources of pluripotent stem cells. Instead, cells used for such research are to be derived from embryos that are “in excess” of what was needed as part of clinical fertility treatment procedures and which have been donated for research purposes. The guidelines also set forth other additional safeguards for obtaining and then for studying pluripotent stem cells by establishing a new review body to evaluate proposals not only on their scientific merits but also on whether they are appropriately sensitive to ethical concerns.

Critics of the research argue that, even with such safeguards and despite the fact that those excess embryos are to be discarded, such research will still depend on destroying human life for its requisite materials. Some critics also contend that NIH should be funding alternative research on “adult” stem cells rather than on embryo-derived stem cells. Experts from NIH and elsewhere say that, although adult stem cell research is warranted, stem cells from embryonic sources appear more versatile for research and anticipated medical applications.

These issues continue to be aired in several forums, including a series of hearings convened by the Labor, Health and Human Services, Education and Related Agencies Subcommittee of the Senate Appropriations Committee—the most recent, held the first week in September. Subcommittee chairman Senator Arlen Specter (R-PA) and ranking minority member Senator Tom Harkin (D-IA) both favor human stem cell research and the two of them are co-sponsoring legislation that explicitly would authorize NIH to support such studies; a comparable bill is pending in the House of Representatives. Whether that legislation will come to a vote in the dwindling time left during the current session seems doubtful, but if it fails to pass, the practical utility of the new guidelines could collapse.