Dental X-Rays Might Lead to Small Babies
Study: Women Who Undergo Dental X-Rays While Pregnant Face Greater
Risk of Having Small Babies
The Associated Press

CHICAGO April 27, 2004 - Women who undergo dental X-rays while pregnant
face an increased risk of having underweight babies, a study found.
The study lacked data on whether babies born to X-ray-exposed mothers
developed any problems associated with low birth weight, including
lung ailments and delays in physical or mental growth.

Still, Dr. Michael Fleming, president of the American Academy of
Family Physicians, called the study "potentially very significant
because it really changes the information that we've believed all
these years."

While doctors and dentists usually are cautious about taking X-rays
during pregnancy, the academy has told pregnant women that medical
and dental X-rays are safe.

Fleming said the study will "make us take a closer look at the data."

Similar findings have been reported in babies born to women exposed
during childhood to radiation for cancer treatment. X-rays generally
involve much lower radiation doses.

The study, which appears in Wednesday's Journal of the American
Medical Association, involved about 4,500 women who gave birth while
enrolled in a dental insurance plan in Washington state between 1993
and 2000.

A total of 1,117 low birth weight babies, or those weighing less than
5 pounds, 8 ounces, were born to study participants. Women who had
had dental X-rays during pregnancy faced about double the risk of
having a low birth weight baby born either prematurely or full-term,
and more than triple the risk of having a full-term underweight baby.

There was no link found between X-rays and the smallest babies, those
born at less than 3 pounds, 4 ounces.

Only 21 women who had low birth weight babies had dental X-rays, all
in the first trimester, when they might not have known they were

The study's lead author, Dr. Philippe Hujoel, a professor of dental
public health services at the University of Washington, said more
research is needed to determine if dental X-rays really are the

Hujoel said it is unclear how dental X-rays might affect fetuses but
theorized that the radiation might cause subtle changes in the
functioning of the mother's thyroid gland, in the neck. Previous
studies have found an increased risk of low birth weight babies in
women with mild thyroid disease, he said.

The researchers lacked information on why the women received X-rays.
Hujoel said that while the X-rays were probably for routine checkups,
they might have been prompted by conditions that could also increase
the risk of low birth weight babies.

In the meantime, Hujoel said, the results should not discourage
pregnant women with dental emergencies such as bad toothaches from
seeking appropriate care, including X-rays. The risks of such
problems might outweigh any dangers from the X-rays, Hujoel said.

Dr. Sally Cram, a Washington, D.C.-area dentist and spokeswoman for
the American Dental Association, said the ADA advises dentists to
avoid giving pregnant women X-rays during the first trimester if

All patients, pregnant or not, should be given protective aprons and
collars that cover the upper body and neck, Cram said.

She said the study reinforces the importance of taking care of any
dental problems before pregnancy.

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