The advertisements are enticing, particularly in a flagging economy: Young women may earn thousands of dollars by selling their eggs.
One California-based agency is offering $100,000 for the eggs of the "right" woman.
But a Tucson doctor and mother is issuing a controversial warning to potential egg donors.
"We really don't know the long-term risks," said Dr. Jennifer Schneider, who practices internal medicine. "These young women may take that as meaning there are no risks. Young women think they are invulnerable.
"But my daughter was like that, too, and at 31 she was gone."
Schneider's daughter, Jessica Grace Wing, a composer and filmmaker, died of colon cancer in 2003, two years after she was diagnosed with tumors in her colon and both ovaries.
Wing had donated her eggs three times, beginning when she was a student at Stanford University.
Her mother fears the egg donations may be linked to the cancer.
Wing's family has no history of any early cancer or colon cancer. Her grandfather died of non-colon cancer, but he was 85.
A DNA tissue analysis performed after Wing's...