While many studies have investigated whether cellphone radiation is harmful, little is known about how the sound of a cellphone ringing might impact a baby in utero. So researchers in New York decided to dig, in part because resident physicians—who regularly use cellphones and beepers at work—seem to have more pregnancy complications. Their study is small and has yet to be peer-reviewed or published, but the researchers say their findings, to be presented at a meeting of the American Congress of Obstetricians and Gynecologists in San Francisco this week, warrant further investigation. "Cycles of normal fetal behavior are definitely disturbed or interrupted by the frequent use of cellphones and beepers," one of the researchers tells the Philadelphia Inquirer. "If you're a baby in-utero and someone wakes you up every hour, you will not be a happy camper."
To test the possible link, they used high-quality ultrasound on 28 pregnant medical residents in their third trimester and observed how the fetuses reacted to the sounds of cellphones ringing and beepers beeping when attached at the hip to the mothers' scrubs (ie, close to the babies' heads). Almost every time, the babies would exhibit the "startle reflex," turning their heads, opening their mouths, blinking more rapidly, etc. The sound, the researcher tells What to Expect, "wakes up and possibly scares the unborn baby." They haven't yet studied what other types of sounds may do this (alarm clocks, car horns, etc.) and what decibel level disrupts the baby, but they say they're already planning future studies. (Meanwhile, talking on cellphones while pregnant has been linked to higher rates of misbehavior in those babies later.)