Thirty-five weeks pregnant, Robin Rodgers was vomiting and losing weight, so her doctor hospitalized her and ordered that she be fed through a tube until the birth of her daughter.

But in a mistake that stemmed from years of lax federal oversight of medical devices, the hospital mixed up the tubes. Instead of snaking a tube through Rodgers’ nose and into her stomach, the nurse instead coupled the liquid-food bag to a tube that entered a vein.

Putting such food directly into the bloodstream is like pouring concrete down a drain. Rodgers was soon in agony.

“When I walked into her hospital room, she said, ‘Mom, I’m so scared,’ ” her mother, Glenda Rodgers, recalled. They soon learned that the baby had died.

“And she said, ‘Oh, Mom, she’s dead.’ And I said, ‘I know, but now we have to take care of you,’ ” the mother recalled. And then Robin Rodgers — 24 years old and already the mother of a 3-year-old boy — died on July 18, 2006, as well. (She lived in a small Kansas town, but because of a legal settlement with the hospital, her mother would not identify it.)

The deaths were among hundreds of deaths or serious injuries that researchers have traced to tube mix-ups. But no one knows the real toll, because this kind of mistake, like medication errors in general, is rarely reported. A 2006 survey of hospitals found that 16 percent had experienced a feeding tube mix-up.

Standards groups have advocated since 1996 that tubes for different functions be made incompatible — just as different nozzles at gas stations prevent drivers from using the wrong fuel.

But action has been delayed by resistance from the medical-device industry and an approval process at the Food and Drug Administration that can discourage safety-related changes.

Hospitals, tube manufacturers, regulators and standards groups all point fingers at one another to explain the delay. Hospitalized patients often have an array of clear plastic tubing sticking out of their bodies to deliver or extract medicine, nutrition, fluids, gases or blood to veins, arteries, stomachs, skin, lungs or bladders. Much of the tubing is interchangeable, and with nurses connecting and disconnecting dozens each day, mix-ups happen — sometimes with deadly consequences.

“Nurses should not have to work in an environment where it is even possible to make that kind of mistake,” said Nancy Pratt, a senior vice president at Sharp HealthCare in San Diego and a vocal advocate for changing the system. “The nuclear power and airline industries would never tolerate a situation where a simple misconnection could lead to a death.”

An international standards group is seeking consensus on specific designs on how tubes for different bodily functions should differ, but the group has been laboring for years and its complete recommendations will take years more. Some manufacturers have used color-coding to distinguish tubes for different functions, but with each manufacturer using a different color scheme, the colors have in some cases added to the confusion.

Advocates in California got legislation passed in 2008 that would have mandated that feeding tubes no longer be compatible with tubes that go into the skin or veins by 2011. But in 2009, AdvaMed, the manufacturers’ trade association, successfully pushed legislation to delay the bill’s effects until 2013 and 2014.

In the meantime, FDA reviewers have begun to question whether feeding tubes that could mistakenly be connected to intravenous tubes should be declared fundamentally unsafe.

The catalyst for those questions, according to internal documents provided to The New York Times, was an application filed in August 2009 from Alan Reid, president of Multi-Med in West Swanzey, N.H., to produce feeding tubes for newborns that go into the stomach using the same connectors as those that go into veins. The FDA was so concerned about the application that it inspected the Multi-Med plant in September and issued a warning letter for Multi-Med’s failure to test or design its pediatric feeding tubes adequately.