May 2007 | Back to Table of Contents

Pulse

Egg-stracting Answers

A Minnesota epidemiologist helps answer questions about the risk of egg donation for research.

When California voters approved $3 billion in funding for stem cell research in 2004, they laid the groundwork for what could be one of the largest stem cell initiatives in the world. They also left the California Institute for Regenerative Medicine, the agency charged with distributing and overseeing the money, with questions: Where would embryonic stem cells that would be used for research come from? And if they came from the eggs of healthy donors, would those women be jeopardizing their health in any way by donating?

The institute asked the National Academy of Sciences to gather experts on the subject to find answers. One of those tapped was Bernard Harlow, Ph.D., head of epidemiology and community health at the University of Minnesota’s School of Public Health. An expert in reproductive epidemiology, Harlow was asked to join a nine-person committee charged with organizing a symposium and publishing a report on the medical risks of oocyte donation.

“I was the token epidemiologist on the committee,” Harlow says, adding that most other members were clinicians who worked in reproductive medicine.

Harlow and his fellow committee members identified potential risks and experts who could address them. Their list included acute problems arising from the process of retrieving eggs such as ovarian hyperstimulation syndrome, which is associated with increased ovary size, accumulation of fluid in the abdomen, and increased concentration of red blood cells, as well as kidney and liver problems. They also looked at the possibility of long-term effects including compromised fertility; the development of breast, ovarian, or endometrial cancers; and the psychological effects of donation.

“There is not much literature on this,” Harlow says of the risks of egg donation. “They’ve tried to do some longitudinal studies around the risk of ovarian cancer and breast cancer among women going through in vitro fertilization, but there haven’t been many studies and the findings are mixed.”

The clinicians and researchers who spoke at the symposium in San Francisco last September and whose comments were the basis of the group’s report, “Medical Risks of Oocyte Donation for Stem Cell Research,” published by the National Academies in February, noted that the studies that have been done show a very low risk for adverse outcomes. “Ovarian hyperstimulation syndrome can be completely prevented with good management, and the concerns around surgical and anesthetic risks were extremely low,” Harlow says. “As for the psychological ramifications, all the studies that were reviewed were very small or not controlled or clinically based; they weren’t methodologically very sound.”

Harlow says they found no increased risk of cancer associated with donation, either. “The caveat is, we know infertility increases the risk for some of these cancers, and we can’t separate that out from oocyte donation or the IVF process and the drugs used for that, and that’s a problem,” he explains. “If we do move into a situation where we develop a cohort of women who begin to donate oocytes for stem cell research, we would want to follow them over time and monitor their health and the long-term consequences.”

Whether women will want to donate their eggs for stem cell research is another issue. Currently, women who donate to oocyte banks or who contract with infertile couples can be paid thousands of dollars. However, the idea of paying women to donate eggs for stem cell research is uncharted territory.

Harlow says he learned a tremendous amount while putting together the symposium. “It’s fun for a nonphysician epidemiologist to work with clinical colleagues,” he says. “They have such a vast understanding of the biological processes involved, and we epidemiologists have such a good understanding of the methodological approaches that are used to evaluate risks associated with clinical procedures. It’s a wonderful blending, and it’s how research should be done.”—Kim Kiser