Reproductive technologies have a long history of freedom from government regulation in the United States, but that record could now face a setback thanks to new embryonic stem-cell research guidelines released this week.

Health, not money, should be the priority of women hoping to sell their eggs to science, the National Academies concluded in a 240-page report published Tuesday. As a result, researchers should be barred from paying women for their eggs.

The recommended prohibition contrasts with the vibrant commercial market already established for human eggs in reproductive medicine. For baby-making, women are now paid handsomely -- in some cases $15,000 or more -- for selling eggs to an infertile couple. And sperm banks routinely pay men from $65 to $500 for their sperm depending on how much is donated and whether the sperm owner releases his identity.

To produce many eggs instead of just one or two in a given month, women take hormones to induce "superovulation." Those drugs, such as Lupron, can cause complications such as ovarian hyperstimulation syndrome, and bleeding or rupture of ovarian cysts.

Those health...