Dental X-Rays Tied to Low Birth Weight
Experts Say Danger Occurs Before a Woman Knows She's Pregnant
April 27, 2004 -- Getting dental X-rays during pregnancy might increase the risk of delivering a low birth-weight baby, new research shows.
After adjusting for other possible causes of low birth-weight babies, such as maternal smoking, University of Washington scientists found that exposure to four "bitewing" dental X-rays more than doubles a woman's risk of having a baby weighing less than 5.5 pounds. And more X-ray exposure, such as full-mouth dental X-rays, increases the risk even more.
The risk was greatest for full-term babies at this higher radiation -- nearly four times the risk of weighing less than 5.5 pounds.
Still, researcher and periodontist Philippe Hujoel, DDS, PhD, -- along with other experts not involved in the study -- tell WebMD that it's too early to say there's a clear danger from getting dental X-rays during pregnancy, a practice that he says is typically avoided.
"'Danger' is an overstatement, because most dentists will not take dental X-rays from the moment they know a woman is pregnant," Hujoel tells WebMD. "But our findings point to a big challenge: What about women who visit their dentists and get dental X-rays when they may not be aware they are pregnant?"
Get Dental Exam Before Pregnancy
In his study, published in this week's TheJournal of the American Medical Association, Hujoel and colleagues reviewed records of more than 1,100 women who gave birth to a babies weighing less than 5.5 pounds. They also examined the infants' birth certificates. These infants were compared to nearly 4,500 normal-weight newborns.
About 10% had dental X-rays performed while they were pregnant, and Hujoel suspects that many -- along with their dentists -- were unaware they were expecting when they had the dental X-rays.
"If anything, our study suggests that if you are considering becoming pregnant, you should have a dental checkup prior to becoming pregnant," he says. "But if you suspect you may be pregnant, you should alert your dentist to this fact, or to be safe, not get dental X-rays unless they are absolutely essential."
The dilemma: During pregnancy, women are at much higher risk to develop gum problems such as gingivitis, and evidence indicates that women with gum disease during pregnancy are seven times more likely to have a baby born too early and too small. The inflammation caused by gum disease is believed to cause certain chemicals to be released in the bloodstream that affect the baby's birth weight and delivery.