File photo shows a pregnant woman reading her ballot paper through a curtain in a booth at a polling station organized at a maternity hospital in the Ukrainian capital Kiev, October 31, 2004. (Mykhailo Markiv/Reuters)

NEW YORK (Reuters Health) -
Children whose mothers used
cell phones frequently during pregnancy and who are themselves
cell phone users are more likely to have behavior problems, new
research shows.

The finding “certainly shouldn't be over interpreted, but
nevertheless points in a direction where further research is
needed,” Dr. Leeka Kheifets of the UCLA School of Public
Health, who helped conduct the study, told Reuters Health.
“It's a wonderful technology and people are certainly going to
be using it more and more,” she added. “We need to be looking
into what are the potential health effects and what are ways to
reduce risks should there be any.”

Kheifets and her team looked at a group of 13,159 children
whose mothers had been recruited to participate in the Danish
National Birth Cohort study early in their pregnancies. When
the children reached age 7, mothers were asked to complete a
questionnaire about their children's behavior and health, as
well as the mother's own cell phone use in pregnancy and the
child's use of cell phones.

After the researchers adjusted for factors that could
influence the results, such as a mother's psychiatric problems
and socioeconomic factors, children with both prenatal and
postnatal cell phone exposure were 80 percent more likely to
have abnormal or borderline scores on tests evaluating
emotional problems, conduct problems, hyperactivity, or
problems with peers.

Risks were higher for children exposed prenatally only,
compared with those exposed only postnatally, but were lower
than for children exposed at both time points.

Kheifets and her colleagues note that a fetus's exposure to
radiofrequency fields by a mother's cell phone use is likely
very small. However, they add, research has shown that children
using cell phones are exposed to more radiofrequency energy
than adults, because their ears and brains are smaller.

Because cell phone use was so infrequent among children in
the study - 30 percent of kids were using a cell phone, but
just 1 percent used a cell phone for more than an hour a week -
radiofrequency exposure seems unlikely to have caused any
behavior problems, they say.

“Another possible explanation for the observed association
might be the lack of attention given to a child by mothers who
are frequent users of cell phones,” the researchers suggest.
They note that mothers who used cell phones frequently were of
lower socio-occupational status, more likely to have mental
health and psychiatric problems, and more likely to have smoked
while they were pregnant.

No matter what the factors behind the association are - if
there indeed is a real relationship between cell phone use and
behavior problems–one simple way to reduce exposure to cell
phones would be to use hands-free technology, Kheifets said in
an interview.

Editorialists writing in the journal raise the question of
whether the publication of these findings may scare people for
no reason.

Kheifets and her team believe that while their findings are
preliminary, they should be reported. “We felt that the public
is quite capable of dealing with proper information,” the
researcher said. “One shouldn't really try to be paternalistic
about it.”

SOURCE: Epidemiology, July 2008.