Treat gum disease to prevent preterm delivery

NEW YORK (Reuters Health) May 17 Two studies published this month provide additional evidence that treating gum disease in pregnant women may prevent preterm birth.

"These data suggested that periodontal treatment should be included in prenatal care programs," conclude Dr. Catia M. Gazolla of Vale do Rio Verde University in Tres Coracoes and colleagues, who authored one of the studies. Both reports appear in the May issue of the Journal of Periodontology.

Gazolla and her team found that while pregnant women whose periodontal disease was treated were no more likely to deliver their babies prematurely than women with no gum disease, those who didn't get treatment had a nearly 90-fold increased risk of premature delivery.

And a US team found that the more bacteria women with periodontal disease had in their gums during and after pregnancy, the more likely they were to deliver their infants prematurely.

The Brazilian researchers followed 450 pregnant women, 328 of whom had periodontal disease. Given that it would be unethical to withhold treatment for periodontal disease, the researchers offered it to all of the women with gum disease and 266 received treatment in their second trimester. The remaining 62 dropped out of the study.

Among the women with healthy gums, 4.1 percent delivered infants weighing less than 2,500 grams (5 pounds 8 ounces) before 37 weeks gestation. The rate of preterm, low-birth weight delivery for women with treated periodontal disease was 7.5 percent, not a significant difference.

But among study dropouts, the rate of preterm, low-birth weight delivery was 79 percent.

In the second study, Dongming Lin of the University of North Carolina at Chapel Hill and colleagues investigated the amount of eight different types of oral bacteria and level of antibody response to one of the microbes in 31 pregnant women with periodontal disease, 14 of whom delivered their infants before 37 weeks gestation.

At 22 weeks, levels of seven of the bacteria tended to be higher among the women who delivered prematurely. These women also had levels of an antibody against a bacterium that is a leading cause of periodontal disease that were nearly four-fold lower than in women who delivered full-term infants. This suggests that their immune response to the microbe was suppressed.

After the women gave birth, levels of all eight types of bacteria were at least twice as high in those who had delivered their infants preterm. The researchers also found that levels of all bacteria types increased from 22 weeks gestation to postpartum among women in the preterm delivery group, while they remained about the same in the women who delivered full-term infants.

If other researchers confirm the findings, Lin and colleagues conclude, it may be possible to use antibody levels and oral bacterial "load" to help gauge a pregnant woman's risk of delivering preterm.

Journal of Periodontology, May 2007.