"This is how rationing starts," Sen. Jon Kyl of Arizona, the party's second-in-command in the Senate, declared during a news conference. "This is what we're going to expect in the future."

Said Sen. Lisa Murkowski (R., Alaska): "Those recommendations will be used by the insurance companies as they make a determination as to what they're going to cover."

A government-appointed but independent panel of doctors and scientists said Monday that women generally should begin routine mammograms in their 50s, rather than their 40s. Then, on Friday, the American College of Obstetricians and Gynecologists said that most women in their 20s could have a Pap test every two years - instead of annually - to catch slow-growing cervical cancer. Neither group sets federal policy, and the ACOG's recommendations are aimed at its own members.

Democrats said the recommendations had nothing to do with the health-care bill. Besides, they said, the recommendations - especially the one on mammograms - were deeply flawed.

"It's entirely possible that this panel got it wrong, and I think they did," said Sen. Richard J. Durbin (D., Ill.), the vote-counting Democratic whip.

But the recommendations gave Republicans something new to talk about in making their case that the 2,074-page Senate bill amounts to government-rationed health care.

The timing of the release of the recommendations, though apparently coincidental, couldn't have been worse for majority Democrats.

The developments came as Democratic leaders were working to nail down 60 votes to be able to advance their health-care bill to the debate stage.

One Democrat wasn't taking chances on whether the recommendations had jeopardized access to affordable mammograms.

Sen. Barbara Mikulski (D., Md.) said she would introduce an amendment that would limit the costs of the breast-cancer tests for women 40 and older.

"Otherwise, insurance companies may use this new recommendation as yet another reason to deny women coverage for mammograms," Mikulski said.

That was unlikely, the White House said. "Under health-insurance reform, recommendations like these cannot be used to dictate coverage," said presidential spokesman Reid Cherlin.

The guidelines themselves stress that they are general recommendations for routine screening, not a replacement for the one-on-one health advice that women with various risk factors for breast or cervical cancer get from their doctors in choosing how often to get a Pap or mammogram.

Dr. Diana Petitti, who chairs the task force that made the mammogram recommendations, said: "What does this mean if you are a woman in your 40s? You should talk to your doctor and make an informed decision about whether a mammography is right for you based on your family history, general health, and personal values."

Still, the new recommendations generated enough confusion and raised enough questions to force proponents of the health-care overhaul on the defensive.

Health and Human Services Secretary Kathleen Sebelius has said the mammogram recommendation "does not determine what services are covered by the federal government."

Senate Finance Committee chairman Max Baucus said the health-care bill he authored "doesn't do one single thing to change current law related to the way coverage decisions are made."

"Those decisions will be based only on science and thorough review, just as they are today," said Baucus (D., Mont.). "Research comparing the effectiveness of different treatments for different patients cannot be used for rationing care."

Said Rep. Lynne Woolsey (D., Calif.): "We're not rationing anything. It's a decision between a woman and her doctors."

The specter of the government's making deeply personal medical decisions for millions of Americans - in this case, women - has been propelled in part by the Republican drive to stymie the Democratic bill.

The legislation would require most people to buy health insurance, and the House version would create a government plan that would compete with those offered by private insurers.

The Democratic bill would set up an independent institute to conduct studies. It would not authorize the health secretary to deny coverage solely based on the institute's research.

There are other safeguards. All states except Utah require that insurers cover mammograms, and 20 states require coverage that starts at age 40, according to 2007 data compiled by the National Women's Law Center.