Scientists in the United States are still confronted by a frustrating patchwork system of rules when it comes to governance of research using embryonic stem cells (Nature 465, 852; 2010).

Depending on their funding source and particular circumstances, researchers may need to follow National Institutes of Health (NIH) guidelines for human stem-cell research, federal regulations for research on human subjects, the National Academies' guidelines on human embryonic stem-cell research (as interpreted by local embryonic stem-cell research oversight (ESCRO) committees), or state-funding rules. These rules can be particularly confusing when embryo donors are involved.

Institutional review boards (IRBs) may decide that donation of spare embryos to stem-cell research does not qualify as research on human subjects, despite the guidelines of the National Academies, which state that IRBs should approve all embryo donations. The rejection of new stem-cell lines by an NIH working group indicates that embryo-donation consent forms must meet the general ethical standards laid out in the federal regulations (Nature 465, 852; 2010).

If an IRB declines to review a consent form, researchers find themselves in the odd position of having to follow federal regulations on human-subject research without input from anyone experienced in review of that area. ESCRO committees that are unable to persuade their local IRBs to review the research may end up denying approval on human-subject research grounds.

If the research does not go through an ESCRO committee, or if the committee misses the issue or assumes that the IRB's determination means that the consent form is acceptable, researchers might avoid trouble — until they apply to the NIH registry. By then, the only way to fix the problem is by asking donors for their consent again, which may not be possible for practical reasons.

As I see it, the best way to clean up this mess is for ESCRO committees to include one or two IRB members or for IRBs to review all embryo donations, regardless of whether they officially count as research involving human subjects.