Groups opposed to legislation on the Senate floor this week that would expand federal funding for human embryonic stem cell research (S 5) on Tuesday warned that the measure would lead to the exploitation of women.

“Every embryo used in stem cell research requires at least one human egg, and there is only one source for human eggs —the bodies of young women, [harvested] through a process which poses serious risks to their own health,” Cathy Ruse, senior fellow for legal studies at the Family Research Council, told a press briefing. The council is a conservative advocacy organization.

In what Ruse called “a highly exploitative practice,” she said women are being offered large sums of money to donate eggs. She cited Advanced Cell Technology, a biotech company in Alameda, Calif., that “admits to paying women thousands of dollars to buy their eggs for use in stem cell research. To get the massive numbers of embryos biotech firms say they need, they’ll need a massive number of human eggs, and that is a recipe for the widespread exploitation of women.”

But the company’s CEO denied that massive numbers of eggs would be required for research or treatment purposes and further said complications from egg procurement are infrequent.

The Senate bill would allow federally funded studies only of human embryonic stem cells derived from embryos that are left over from in vitro fertilization procedures and otherwise would be discarded.

Speakers at the briefing said the number of eggs that would be available from those venues will decline over time as fertilization clinics turn to new methods to procure embryos. They also said many of the frozen embryos that might be used for research wouldn’t survive the thawing process.

Those factors would lead researchers to turn to other sources, the speakers said, including financial inducements to vulnerable women.

One of the speakers, Josephine Quintavalle, vice chairwoman of Hands Off Our Ovaries, told of a woman in Romania who she said was approached by “egg brokers.” According to Quintavalle, the woman donated eggs to raise money for her wedding, but the process went awry and she spent 14 days in the intensive care unit and became infertile. Quintavalle added that the woman wouldn’t tell her intensive care doctors that she had undergone the egg procurement procedure.

Quintavalle said it was this case that led the European Parliament to adopt a resolution in March 2005 to prevent trafficking in human eggs.

Another speaker at the briefing, Jennifer Lahl of the Center for Bioethics and Culture Network, described 34 cases of arterial thrombosis she said have resulted from assisted reproductive technologies entailing ovarian stimulation. Fifteen of the cases involved strokes, three involved heart attacks and two cases were fatal, she said.

The speakers also said statistics aren’t available on the frequency of such complications overall, and that data needs to be gathered.

William Caldwell, CEO of Advanced Cell Technology, said in an interview that his company and most other companies doing stem cell research rely on “outside third parties” to review whether egg donation procedures abide by ethical safeguards. Those groups develop and review protocols to protect individuals undergoing egg donation, he said, adding that his company has developed a way to procure embryonic cells used to develop stem cell lines without killing the embryo itself.

Caldwell said compensation of donors by the company complies with applicable state laws. In Massachusetts, for example, compensation is only for direct medical expenses. State laws permitting, “we will cover out-of-pocket expenses” such as transportation and day care expenses, he said. He confirmed that the company pays “thousands of dollars” in some cases but noted that considerable time and expense is involved in the donation process.

“Any time you have a procedure where you’re involved with tampering with the human body you have risks,” he added. “But I don’t think you see many complications.” Caldwell also said cloning techniques will allow embryos to be procured without direct egg donations and that therapies are being developed that could make it possible to produce large quantities of stem cells from single embryos, meaning massive quantities of embryos wouldn’t be needed.

Michael Werner, a consultant for the Biotechnology Industry Organization, said the legislation before the Senate “really has very little to do with what is being discussed” regarding the exploitation of women. The measure only allows for federally funded studies of embryos that would be discarded, requires informed consent by egg donors and bars payment of donors, he noted.

The bill also would create a regulatory structure at the National Institutes of Health and would create safeguards that do not now exist, Werner said, adding that it could turn out that embryonic stem cells are used more for screening purposes and less for treatment, in which case fewer embryos would be needed.

Werner also pointed out that if more embryos are needed, creating the NIH regulatory structure would allow better protection of women. The research needs to go forward to determine if it can be done in a way that requires fewer embryos, he added.