A bacterium associated with periodontal disease can trigger preterm births or stillbirths in mice, say researchers in the April issue of the Journal of Infection and Immunity.
Fusobacterium nucleatum is an anaerobic gram-negative bacterium found in plaque and is associated with periodontal disease. It has been found in the placentas and amniotic fluid of up to 30 percent of women who have undergone premature labor.
Researchers injected laboratory mice with F. nucleatum taken from the placentas and amniotic fluid of women who had experienced preterm deliveries. These mice gave birth to stillborn pups within 72 hours of injection, reported investigators from the Case Western Reserve University, Cleveland, and Duke University, Durham, N.C.
"The number of bacteria can increase 10,000 fold when periodontal disease is present," said lead investigator Yiping Han, Ph.D., a microbiologist at CWRU. "This bacterium takes the opportunity to enter the bloodstream when bleeding occurs with gum disease."
Dr. Han added that in humans, periodontal disease and pregnancy—with its hormonal changes—both challenge the immune system, which may have a harder time warding off the bacteria and keeping in check the numbers of the bacteria normally present in the mouth.
When the immune system is compromised through periodontal disease and pregnancy, the F. nucleatum can target the placenta and amniotic fluid, leading to a localized infection in the uterus that can trigger premature labor, Dr. Han said.
"Periodontal disease is treatable and preventable," said Dr. Han. She advises women who are thinking about getting pregnant or are pregnant to visit their dentists for check-ups and maintain healthy oral hygiene practices of brushing and flossing.
