If you're a woman and you get x-rays, the technician always asks if you're pregnant to protect against direct radiation to the reproductive organs, but a new study in this week's Journal of the American Medical Association may change those guidelines a little because it emphasizes a link between low dose dental radiation and low birth weight.
Medical radiation has already been associated with low birth weight, but it's not clear why. Some theories point to the reproductive organs, others to the thyroid. The study says dental radiation was a good test of both theories because dental x-rays are aimed near the thyroid. While for women, the reproductive organs are protected by a lead apron.
"Currently, the guidelines say that women who are pregnant are eligible for receiving very low dose diagnostic radiation to the head and neck. Because up until now, people assumed that head and neck radiation will not have any adverse affects on pregnant women. They assumed that only direct radiation to the uterus or the fetus would be associated with adverse pregnancy outcomes," explains Dr. Philippe Hujoel, University of Washington.
The university study followed the health records of more than 1,100 women over a seven year period and they found there was a connection between dental x-rays and low birth weight deliveries. Most women know to avoid x-rays when they're pregnant, but since two-thirds of the women in this study were exposed to the radiation during their first trimester, researchers believe it's likely many were going to the dentist before they knew they were pregnant.
However, don't avoid the dentist. Regular visits are especially important during pregnancy. This just means that women who are trying to get pregnant may choose to forego an x-ray, if it can be avoided.