Mom's Gum Disease Raises Risk of Preterm Birth

NEW YORK (Reuters Health) - Women who develop gingivitis (gum disease) during pregnancy, as many do, are at increased risk for delivering prematurely and of delivering an infant of low birth weight, according to a study conducted in South America.

Periodontal therapy to get rid of the bacteria that dwell in the plaque that coats the teeth significantly lowers the risk of preterm/low birth weight (PT/LBW), according to a report in the Journal of Periodontology.

"Ideally women should include a visit to their dentist or periodontist prior to becoming pregnant so that they can begin their pregnancy without periodontal infections," Dr. Kenneth A. Krebs, president of the American Academy of Periodontology told Reuters Health.

"During their pregnancy, they should remain motivated to maintain a high level of oral hygiene," he added. "If periodontal infection is diagnosed at any time during pregnancy, a woman will want to speak with her periodontist about treatment to determine if it is necessary during pregnancy in order to reduce the risk of preterm birth and low birthweight infant."

Studies have shown that infection in the mother plays a key role in about half of all cases of premature delivery, Dr. Nestor J. Lopez from the University of Chile in Santiago and colleagues who conducted the study note in their report. Periodontal infections may be among the maternal infections associated with this and other adverse pregnancy outcomes. There's evidence that some periodontal pathogens can cross the placenta and produce infection in the fetus. In their study, Lopez and colleagues randomly assigned 870 pregnant women at low risk for PT/LBW but who had gum disease to no periodontal therapy or to periodontal therapy consisting of plaque control, scaling, and daily rinsing with bacteria-busting chlorhexidine.

The researchers found that the incidence of PT/LBW was markedly lower in the women who received periodontal therapy for their gum disease compared with those who received no treatment for their gum disease. The untreated women had a more than threefold higher risk of PT/LBW.

The significant association between untreated gingivitis and preterm birth remained strong after adjusting for the major risk factors for preterm delivery, "suggesting that gingivitis is an independent risk factor for PT/LBW," the investigators say.

In this study, periodontal therapy in women with pregnancy-associated gingivitis reduced the PT/LBW rate by 68 percent, which supports two previous intervention studies in which periodontal treatment reduced the incidence of PT/LBW between 71 percent and 84 percent in pregnant women with moderate to severe chronic periodontitis, Lopez and colleagues note.

"Pregnancy-associated gingivitis is a preventable and easy to treat disease," Krebs noted in a statement. "Although it is still not known what are the precise mechanisms involved in the association between periodontal infections and preterm birth, to date, no harmful damaging effect caused by periodontal intervention in pregnant women has been reported."

SOURCE: Journal of Periodontology, November 2005.