Oral Bacteria May Cause Preterm Births

Using new DNA fingerprinting technology to find bacteria that cannot be cultured and grown in a laboratory, researchers have discovered oral bacteria in the amniotic fluid of a woman in preterm labor.

Lead researcher Dr. Yiping Han, a microbiologist in the department of biological sciences at the Case Western Reserve University School of Dental Medicine (Cleveland, OH, USA), has spent about three years searching for this link.

Dr. Han and colleagues found the link during a pilot study of 34 women undergoing amniocentesis. Six of the women delivered before 30 weeks and had a higher risk for possible infections. Only one woman was found to have an infection. Tests of the amniotic fluid revealed the presence of Bergeyella bacteria, one of 700 bacteria found in the mouth. Since it could not be grown in culture, this bacterium could not be studied until new techniques such as polymerase chain reaction (PCR) became available to track the DNA of bacteria. The study continues Dr. Han's research into the suspicion that oral bacteria, once entering the blood, can cause a host of health problems, including preterm labor.

Finding how the bacteria got into the amniotic fluid might suggest a method of prevention. It is known that women can contract a uterine infection vaginally while pregnant. A pathway of infection has been suspected through the mouth in pregnant women with periodontal disease, where the oral bacteria enter the blood through bleeding gums. However, the woman with the infection showed no signs of post-partum periodontal disease. The study results were reported in the April 2006 issue of the Journal of Clinical Microbiology.

"If periodontal disease is not present, then this raises more questions about how the bacteria got into the amniotic fluid,” observed Dr. Han.



Related Links:
Case Western Reserve U.