According to a new US study, pregnant women with gum disease are more likely to give birth prematurely than mothers-to-be with good oral health.
The research by scientists at the University of Pennsylvania suggests that successful treatment for gum disease can cut the risk of pregnant women giving birth early, reports the BBC.
The study of 160 women showed that those whose gum disease was not treated successfully were three times more likely to give birth before 35 weeks.
It has been previously established that severe gum infections cause an increase in the production of prostaglandin and tumour necrosis factor, chemicals which induce labor, to be produced.
The study enrolled women who were between six and 20 weeks' pregnant.
All of the volunteers had gum disease. These women were given treatment, which was successful in one third of the cases.
The results showed a 'strong and significant association' between successful treatment and full-term births.
Those whose treatment did not work were 'significantly more likely' to give birth before 35 weeks.
However, UK experts warned that this was a small study and further research was needed.
The study was presented to the annual conference of the American Association for Dental Research.