Results of a survey indicate that more than half of infertility patients in the U.S. would be willing to donate their unused embryos for stem cell research.

"Until now, the national debate about stem cell research has primarily involved lawmakers, advocates, and academic and religious leaders," Dr. Anne Drapkin Lyerly told Reuters Health. The perspectives of infertility patients, "who created embryos in hopes of having a baby and who now face the very personal moral dilemma of what to do with embryos they themselves will not use have not been represented."

"What we found was that, in large numbers, these patients -- who have both legal authority and moral responsibility for the embryos -- choose research as the preferred option for unused embryos," said Lyerly, of Duke University, Durham, North Carolina.

On Wednesday, President George W. Bush vetoed legislation to expand federally funded embryonic stem cell research.

Among 1,020 infertility patients asked about their intentions for embryos remaining after fertility treatment, 495 (49 percent) indicated that they were somewhat or very likely to donate their unused embryos for general medical research purposes.

There was even greater interest in donating unused embryos specifically for stem cell research, with 60 percent indicating a willingness to do this, according to a report in Science, published online June 21.

"This is consonant with the conclusions of the American public, the majority of whom support stem cell research," Lyerly said.

"Perhaps most surprisingly," note Lyerly and co-author Ruth R. Faden of Johns Hopkins, Baltimore, in their report, 28 percent of those surveyed said they would be somewhat or very likely to donate embryos to improve cloning techniques for medical science.

The results of this survey suggest that many more embryos may be available for research in the U.S. than previously estimated. "In contrast to previous estimates that less than 3 percent, or 11,000 of the 400,000 embryos currently stored are available for research, our data suggest a 10-fold increase in these estimates," Lyerly explained.

The strong preference among infertility patients for using embryos for research as opposed to discarding embryos or even giving them to another couple to have a baby is a key finding, Lyerly added.

"In the national debate," she explained, "the prevalent view is that a respectful or responsible stance toward the embryos would entail giving it a chance to develop into a baby. In contrast, our data reflect a view described by many infertility patients, that a responsible stance means not allowing the embryos to become children without the involvement or care of those who created them."