Study Links Dental X-Rays during Pregnancy to Smaller Babies

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Pregnant women are advised to avoid having medical x-rays taken to avoid harming the developing fetus. Now a study published by the Journal of the American Medical Association links dental x-rays administered during pregnancy to low birthweight babies.

Philippe P. Hujoel of the University of Washington and his colleagues studied the records of thousands of women who received dental treatments between 1993 and 2000 in Washington State. The team compared the list to birth certificate records and found that 1,117 of the patients for whom they were able to obtain dental records had delivered low birthweight infants. According to the report, expectant mothers who underwent dental radiography were three times more likely to have a full-term baby weighing in at under five pounds, eight ounces than were women who had not had dental x-rays. "We were surprised by the finding, but it does bear out previous studies that found that other types of diagnostic radiation, such as diagnostic radiation for spine problems, also were associated with low birthweight," Hujoel says.

For now, it remains unclear what causes the association. "We don¿t know whether radiation affects neurohormonal mechanisms in the head and neck region, such as thyroid function, or whether factors unrelated to the x-rays are to blame," Hujoel remarks. In addition, he cautions that the results do not warrant avoiding treatment for serious dental problems, although elective dental x-rays for mom should probably be postponed until after the baby arrives.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe