Pregnant women who are given dental fillings - even those that contain mercury - do not increase their chances of giving birth to very small babies. These results contradict long-held concerns that it's unsafe for women to get mercury-amalgam dental fillings during pregnancy, due to the potential harm mercury may pose to an unborn child. Ideally, women should get a thorough dental exam before becoming pregnant, to treat any problems ahead of time. But if it turns out that you have a cavity during pregnancy, then get it filled, no question about it. According to the World Health Organization, billions of damaged or decayed teeth are repaired with dental fillings each year. Many contain mercury, which research shows can cause low birth weight in infants, and problems in brain development. However, the most popular alternative to mercury in fillings is a resin-based material, which may cause its own form of harm by releasing estrogen-like substances that may also endanger a pregnancy, they point out. To investigate if mercury-based fillings have any effect on pregnancy, Researchers from the University of Washington, reviewed the dental history of 1,117 women who gave birth to small babies, weighing less than 2,500 grams, or 5 pounds 8 ounces. The investigators compared them to 4,468 women who gave birth to normal weight infants. Among the women included in the study, nearly 5 percent had received at least one filling that contained mercury during their pregnancies. They did not appear to have any increased risk of giving birth to tiny babies. In fact, even women who received up to 11 filings during pregnancy were no more likely to have low birth weight babies. Receiving resin-based fillings also appeared to have no effect on women's risk of having tiny babies, it was found. The findings do not provide support to the hypothesis that mercury-containing dental amalgams placed during pregnancy affect birth weight.
American Journal of Epidemiology,
May 2005