The association between the low birth weights in full-term babies (infants who had 37 or more weeks of gestation) and diagnostic radiography performed during routine dental care requires more investigation, Hujoel said, because the explanation for the low birth weights (less than 2.5 kilograms, or 5 pounds, eight ounces) is not clear.
"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 said. "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 birth weight."
Hujoel notes that the results of the study should not prevent pregnant women from having diagnostic dental X-rays if they are suffering from a dental problem. Most dentists are very cautious about taking X-rays during pregnancy. Patients should always inform their dentists about any potential pregnancy so that the dentist can postpone any elective dental X-rays until after delivery. Hujoel points out that the move toward digital radiography will drastically reduce the radiation doses needed for current techniques.
"When we first noticed this association, we were very surprised," Hujoel
said. "Currently the care gu
Contact: Pam Sowers
University of Washington