WASHINGTON – Too many pregnant women who want to avoid a repeat cesarean delivery are being denied the chance, concludes a government panel that urged doctors to rethink litigation-spurred policies that have swung the pendulum back toward the days of “once a C-section, always a C-section.”

Fifteen years ago, nearly 3 in 10 women who had a first C-section were able to deliver their next baby vaginally, a trend called VBAC for “vaginal birth after cesarean.”

Now that rate has dropped to 1 in 10, in part because a third of hospitals and half of physicians ban women from attempting VBAC, a panel of specialists convened by the National Institutes of Health said Wednesday.

But VBAC remains a safe alternative for the right candidates, and when those women try labor, between 60 percent and 80 percent of the time they do give birth vaginally, the NIH panel concluded. It urged that doctors offer mothers-to-be an unbiased look at the pros and cons, so they can decide for themselves.

“We believe that many women should have an opportunity to give it a try,” said panelist and Delaware obstetrician Dr. Nancy Frances Petit of the U.S. Uniformed Health Services.

Overall, nearly a third of U.S. births are by cesarean, an all-time high. Cesareans can be lifesaving but they come with certain risks — and the more C-sections a woman has, the greater the risk in a next pregnancy of problems like placenta abnormalities or hemorrhage.

Decades ago, doctors almost always recommended a repeat C-section, worried that the rigors of labor could cause a uterus scarred from the first surgery to rupture. But in 1980, government experts concluded that many mothers could safely deliver vaginally the next time, citing evidence that their risk of a uterine rupture was less than 1 percent.

Yet the last decade saw the pendulum swing back again: Among 19 states that track VBAC, 92 percent of women had a repeat cesarean for their next delivery in 2006. And in 1999, the American College of Obstetricians and Gynecologists issued guidelines saying VBAC should be attempted only in hospitals equipped for immediate emergency surgery — and many smaller and rural hospitals aren’t.

What sparked the latest shift? It’s partly concern over litigation, the NIH panel said, because while a uterine rupture remains very rare, it can be devastating to the family and end in a high-dollar lawsuit.

Case-by-case decisions are crucial, the panel said, because there may be instances where another C-section is better for the baby but not for mom or vice versa.

Who’s a good candidate? The panel said that needs further study. But in general, VBAC is for women who’ve had one prior C-section done with a “transverse” scar, the most common kind today, said panel chairman Dr. F. Gary Cunningham of the University of Texas Southwestern Medical Center at Dallas. Women should be otherwise low-risk, he said: Not carrying multiples or a large baby, being obese or having high blood pressure or diabetes.

“There’s still a lot we don’t know about which women will be successful in having a VBAC, but we believe it’s essential that women’s desires and preferences be respected throughout the decision-making process,” Cunningham said.

Don’t try to pre-judge candidates, said Dr. Emily Spencer Lukacz of the University of California, San Diego.

“All women who have prior cesarean delivery should talk to their providers about VBAC,” so they can decide on a case-by-case basis if it makes sense, Lukacz said.

It can be difficult for women to find a doctor or hospital that offers VBAC, said Debra Bingham of Lamaze International. She points to California, which now lists VBAC availability for every hospital on a Web site: http://www.calhospitalcompare.org.

NEW YORK – A troublingly high number of U.S. patients who are given angiograms to check for heart disease turn out not to have a significant problem, according to the latest study to suggest Americans get an excess of medical tests.

The researchers said the findings suggest doctors must do better in determining which patients should be subjected to the cost and risks of an angiogram. The test carries a small but real risk — less than 1 percent — of causing a stroke or heart attack, and also entails radiation exposure.

“We can do better. There is no doubt in my mind,” said Dr. Ralph Brindis of the University of California, San Francisco, one of the study’s authors.

Every year in the United States, more than a million people get an angiogram, in which a thin tube is inserted in the arm or groin and threaded up to the heart to check for blocked arteries that could lead to a heart attack. Dye is injected through the tube to make blockages show up on X-rays.

Angiograms are often given to patients who might be having a heart attack or have symptoms that suggest a serious blockage. They are also sometimes done on people who may have some less clear-cut symptoms, like shortness of breath, or no symptoms but some risky traits like high cholesterol and an abnormal result on another heart test. This group accounts for about 20 to 30 percent of angiogram cases.

In the study, nearly two-thirds of the patients in this second group were found to have no serious blockages.

The researchers could not establish why so few proved to have heart disease. But Dr. Harlan Krumholz, a Yale cardiologist and health-outcomes researcher unconnected to the study, said he thinks the problem arises because doctors are afraid of missing something, and also getting sued.

“We fear doing too little,” he said. “I think that we developed a culture where people feel that doing more and knowing more is always the proper course. What that does is sometimes lead us to overuse.”

Researchers said more study is needed to sort out how to better select patients for an angiogram. For now, experts suggest patients in the category studied by the researchers question their doctors about the need for the test and the risks and alternatives.

To decide whether someone needs an angiogram, a doctor assesses a patient’s medical status and symptoms, and usually tries a noninvasive test, such as an ultrasound of the heart or having the patient run on a treadmill. It is this gatekeeper process that needs improvement, researchers suggested in Thursday’s issue of the New England Journal of Medicine.

They sifted through records of nearly 2 million angiograms performed at 663 U.S. hospitals between 2004 and April 2008. The data came from a registry kept by the American College of Cardiology, which sponsored the study.

The researchers focused on about 400,000 patients who raised doctors’ suspicions but had no known heart disease and weren’t getting emergency heart treatment.

In those people, the test revealed no significant artery blockages 62 percent of the time. That doesn’t mean all those tests were unnecessary, but the rate is high enough to suggest doctors could do a better job of choosing who really needs the exam, researchers said.

The researchers suggested doctors should be less willing to order an angiogram for symptom-free patients, a group that made up 30 percent of the study sample.

Beyond that, further study might help doctors better gauge heart disease risk from a patient’s symptoms and characteristics like age and history of other diseases, said lead author Dr. Manesh Patel of Duke University.

Doctors could also use more research to help them choose the right noninvasive test, which might reduce the need for angiograms, he said.

Choices now include the treadmill test, injecting a radioactive solution to trace blood flow within the heart, doing an ultrasound to watch the walls of the heart moving, and doing a specialized CT scan that has recently shown promise.

“We still haven’t figured out, in all honesty, the best way of applying these technologies,” Brindis said.

In fact, one of the study’s co-authors — Dr. Pamela Douglas of Duke — just received a $32.5 million federal grant, the largest ever for heart imaging, to compare various heart imaging tests and see which ones do the most to prevent heart attacks, deaths and hospitalization.

Experts praised Patel’s study.

Some previous reports have found similar results, but the new study is so huge “we can now feel comfortable these aren’t isolated findings, this is for real,” said Dr. Michael Lauer, director of the division of cardiovascular sciences at the National Heart, Lung and Blood Institute.

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On the Net:

New England Journal: http://www.nejm.org

CHAMPAIGN, Ill. – As they scrambled recently to trace the source of a salmonella outbreak that has sickened hundreds around the country, investigators from the Centers for Disease Control and Prevention successfully used a new tool for the first time — the shopper cards that millions of Americans swipe every time they buy groceries.

With permission from the patients, investigators followed the trail of grocery purchases to a Rhode Island company that makes salami, then zeroed in on the pepper used to season the meat.

Never before had the CDC successfully mined the mountain of data that supermarket chains compile.

“It was really exciting. It was a break in the investigation for sure,” CDC epidemiologist Casey Barton Behravesh said.

At least 245 people in 44 states have been sickened in the outbreak. That includes 30 in California, 19 in Illinois, 18 in New York and 17 in Washington state.

The victims included Raymond Cirimele, a 55-year-old Chicago man. He said no one asked for his shopper-card data, but he would have provided it if someone had.

“I don’t have any secrets, so I’m not worried about it,” he said. “It’s kind of like the whole airport security and all that. I’d rather fly on a safe plane.”

Shopper cards have been around for more than a decade, offering customers discounts in exchange for letting supermarkets track their buying habits. The cards are used to build customer loyalty and help stores market their products.

The first case in this salmonella outbreak was reported last summer, and by November, CDC investigators were examining a multistate cluster of cases.

Through interviews and questionnaires, investigators suspected some kind of Italian meat was the culprit, but people couldn’t remember what brand they bought, Behravesh said.

So the CDC asked supermarkets for certain buying information on seven victims in Washington state, focusing on suspect products rather than everything the customers had bought, Behravesh said. “We didn’t care about the brand of toilet paper people were buying,” she said.

Of those seven people, five had bought Italian meats made by the Rhode Island company, Danielle International Inc., Behravesh said.

Further investigation — including the use of data from other victims’ shopper cards — pointed to salami made by Danielle and, more specifically, the imported pepper it was coated in. That came from two spice suppliers in New York and New Jersey. All three companies have since recalled some products.

The CDC would not say how many patients gave access to their accounts or were asked to do so, but Behravesh said most agreed.

“Most of the time when a person gets really sick with a food-borne pathogen, they’re very happy to talk with us and try to help out with the investigation,” she said.

Some privacy advocates, though, are troubled.

Longtime shopper-card critic Katherine Albrecht, director of a group called Consumers Against Supermarket Privacy Invasion and Numbering, said she worries that the practice could lead to a switch from a voluntary system to mandatory use of such cards.

“That sends chills down my spine,” she said.

Some state and local health agencies have used shopper cards to trace cases of food poisoning. Before this outbreak, the CDC had tried it a few times, too, but without success, Behravesh said.

Some supermarkets have also used shopper-card information to notify customers by letter or automated telephone call that a product they bought has been recalled.

Health authorities trying to trace the source of a food-poisoning outbreak typically ask victims what they bought and what they ate. But without receipts or other hard evidence, they often find themselves at the mercy of people’s memories.

Several large supermarket chains did not respond to requests for comment on health investigators’ use of shopper cards, but Costco — where Cirimele bought meat that was later recalled — said it provided data to the CDC once customers gave their OK.

“In this instance, we actually worked very closely with the CDC,” said Christine Summers, the Issaquah, Wash., chain’s director of food safety. “They ask, `Did this member purchase products A, B or C in this time frame?’ and we tell them, `Yes, they did’ or `No, they didn’t.’”

Supermarkets generally will supply information to health authorities if customers consent, said Jill Hollingsworth, vice president of food safety at the Food Marketing Institute, a trade group for groceries in the U.S.

Bruce Chassy, a food safety professor at the University of Illinois at Urbana-Champaign, said he is intrigued by the new means of tracing food-poisoning cases. He noted it can be extremely difficult to get to the bottom of outbreaks caused by relatively minor ingredients.

“Cantaloupes and eggs are easy,” he said. “The fact that it’s only an ingredient in products in other things, that makes it really hard to track.”

J. Kathryn MacDonald, an epidemiologist with the Washington state Health Department who worked on the salmonella outbreak, such some advocates’ privacy fears are unfounded.

“This is not being used as a tool for open-ended trawling through many records hoping to find something,” MacDonald said. “The records are treated with the same level of confidentiality as would medical records.”