DURHAM, N.C. -- In a survey of over a thousand patients who have created and frozen embryos as part of fertility treatment, 60 percent said they would be likely to donate unused embryos for stem cell research, according to a study led by researchers at Duke University Medical Center and Johns Hopkins University. The researchers published their findings online in the June 21, 2007 Science Express, the online component of the journal Science, and the study will be published in the journal's July 6, 2007 print issue.
These findings suggest that the number of embryos potentially available for stem cell research may be 10 times higher than previous estimates, resulting in a potential 100-fold increase in the number of stem cell lines -- groups of stem cells derived from a single source -- available for federally funded research.
Moreover, current federal policies do not reflect the preferences of infertility patients who have faced the very personal moral challenge of deciding what to do with their frozen embryos, according to the study.
"This has significant implications for potential policy change on stem cell research," said Anne Drapkin Lyerly, M.D., an obstetrician/ gynecologist and bioethicist at Duke and lead investigator on the study. "Previous research indicates that there are approximately 400,000 frozen embryos stored in the United States; if half of those belong to people who are willing to donate embryos for research, and only half that number were in fact donated, there could still be 100,000 embryos available for research." Earlier estimates placed the number of available embryos at about 11, 000, she said.
The researchers sent questionnaires to 2, 210 patients at nine infertility centers across the United States, asking them about their intentions for the frozen embryos they currently had stored. The study was funded by the Greenwall Foundation and the National Institutes of Health.
While 49 percent of those who responded indicated that they were likely to donate some or all of their excess embryos to research in general, the number increased to about 60 percent when the questions were more specific, asking about stem cell research in particular, and about research aimed at developing treatments for human disease or for infertility, Lyerly said.
Among those surveyed, research proved to be the most desirable option for disposition of excess embryos, according to the study; other options, including donation to another infertile couple or destruction of the embryos, were far less desirable. Infertility patients proved more likely to support donating unused embryos to research than giving them to another couple or simply destroying them, possibly because they feel a responsibility to the embryos which actually precludes allowing them to develop into children to be reared by other people, or to be destroyed without benefit, Lyerly said. People undergoing fertility treatment may end up with anywhere from one to more than 20 unused embryos at the end of the process.
Stem cells have the ability to become any type of cell present in the human body, so it may be possible to use them in the future to treat many types of diseases, from autoimmune disorders to cancer, by generating healthy cells to replace damaged ones. Embryonic stem cells are more versatile than their counterparts derived from adults or from umbilical cord blood.
Currently, federal funding for embryonic stem cell research is limited to research on stem cell lines derived from embryos before August 2001, and may not be used for any research in which an embryo is destroyed. Funding from private or state funding sources is growing, but is still insufficient, Lyerly said. President Bush has vowed to veto recent federal legislation that would loosen current limitations on stem cell research.
"For these people, research may prove to be the most acceptable and morally preferable option," she said.
Ruth Faden from the Johns Hopkins Berman Institute of Bioethics coauthored the paper.