Even healthy expecting women can be at risk for pregnancy problems caused by oral bacteria, researchers from Case Western Reserve University have warned.
They have begun to understand how and which bacteria from the 700 species living in the mouth are responsible for the increasing numbers of preterm and stillbirths.
Yiping Han, from the department of periodontics in the School of Dental Medicine, led the study that found several new bacteria originating in the mouth travel through the blood to cause an inflammatory reaction in the placenta and eventually cause a range of health issues from miscarriages to stillbirths.
Researchers have been baffled why oral bacteria have shown up in the placenta or amniotic fluid of pregnant women.
The researchers found that after injecting the blood in the tails of pregnant mice with saliva from healthy people and dental plaque from those with periodontal disease, oral bacteria continued to grow in the placentas after it had left the mice blood 24 hours later.
Prior to Han's work in connecting oral bacteria to the problems in pregnancy, it was thought that infections were transmitted through the vaginal tract.
Information from Han's previous studies over the past decade shows that oral bacteria can be transported through the blood when there is a cut in the mouth's lining or an oral health problem such as gingivitis or periodontitis which breaks down the defenses in the mouth's lining that block or prevent bacteria from entering the bloodstream.
According to Han, this suggests that even healthy pregnant women should be concerned bacteria that normally lives in the mouth can enter the blood stream and make their way into the placenta's immune-free environment to ignite an inflammatory reaction that can lead to premature or stillbirths.
The findings were featured in the spotlight section in a recent Infection and Immunity. The study was also reported on the home page of the American Society for Microbiology.