BALTIMORE — Doctors and scientists from Harvard and Yale medical schools warned this week that pregnant mothers limit their unborn babies exposure to potentially harmful radiation by keeping cell phones away from their tummies because of the possible effect on brain development.

The doctors offered the advice during the Pediatric Academic Societies annual meeting in Baltimore where they also said parents should limit their children’s use of cell phones, iPads and other wireless technology because it can cause behavioral and concentration problems.

There is little research on the effect of the microwave radiation and radio frequency radiation emitted by wireless devices on children, but the doctors said early studies provide enough evidence to suggest that parents should take caution.

The doctors’ comments could stoke a longtime debate over the health dangers of cell phones, but the industry disputed their warning.

The CTIA, the association representing the U.S. wireless communications industry, including carriers, suppliers and manufacturers, cited a Food and Drug Administration statement that there is not enough evidence to show that cell phones can cause a health risk.

“CTIA and the wireless industry defer to the scientific community when it comes to cell phones and health effects,” the group said. “The peer-reviewed scientific evidence has overwhelmingly indicated that wireless devices do not pose a public health risk for adults or children.”

The group said, in addition to the FDA, the World Health Organization, American Cancer Society and numerous other international and U.S. organizations and health experts, have said the scientific evidence shows no known health risk because of the radio frequency energy emitted by cell phones.

“The FCC has determined that all wireless phones legally sold in the United States are ‘safe,’” the association said. “The FCC monitors scientific research on a regular basis, and its standard for RF exposure is based on recommended guidelines adopted by U.S. and international standard-setting bodies.”