Teenagers are more likely to have hearing loss if their
mothers smoked during pregnancy, according to a new study that included audio
tests of close to 1 000 youths.
Researchers said that although the link was "relatively
modest", even limited hearing loss can have implications for kids'
learning and social skills -- so it's important to reach out to those who might
need help, and to prevent as much exposure as possible.
"The findings should be part of all our efforts to get
people not to smoke, and especially not to smoke when they're pregnant,"
said Dr Michael Weitzman, a child health researcher from the New York
University School of Medicine, who led the study.
Range of problems
Past research has tied smoking during pregnancy to a range
of childhood problems, including asthma and learning disabilities. In another
study, Weitzman and his colleagues found exposure to second hand smoke during
adolescence was linked to hearing loss, based on blood tests for
This time they analysed data on a group of 12- to
15-year-olds who underwent hearing tests in 2005-2006 as part of a national
health survey, and whose parents were asked about smoking during pregnancy. The
hearing exams were done in both ears to see if kids had any trouble picking up sounds at different pitches.
Just over 16% of youths had moms who smoked while pregnant,
the study team reported in JAMA Otolaryngology -- Head & Neck Surgery. Those
kids were especially at risk for hearing loss at the lower frequencies of human
speech: one in six had hearing problems in one ear, compared to one in 14 whose
moms didn't smoke. Weitzman said many teens with mild hearing loss don't realise
they have a problem, but that it can lead to irritability and trouble in school.
Reduced oxygen flow
What's more, he told Reuters Health, it's possible the mild
hearing loss measured in some adolescents will only get worse in adulthood.
Hearing researcher Abbey Berg from Pace University in New York said the
findings "make sense", given what is known about risks to the baby
when a woman smokes during pregnancy, including reduced oxygen flow.
"There are also toxins in the cigarettes, as well that
we don't even know necessarily what those are and what the effects of those
are," said Dr Josef Shargorodsky, from Massachusetts Eye and Ear Infirmary
and Brigham and Women's Hospital in Boston."There are so many other risks
of smoking in pregnancy," Shargorodsky, who wasn't involved in the
research, told Reuters Health. "Preventing exposures is the most important
"Berg, who also didn't participate in the new study,
said children who have been exposed can be counselled growing up about how to
prevent further damage to their hearing."These kids could be monitored and
hearing conservation and hearing education could be started at a very young
age," she told Reuters Health. Weitzman agreed that it's important to spot
young people with hearing trouble early."Parents might really want to
consider having their 12- to 15-year-olds undergo hearing tests if they smoked during
pregnancy," he said.