A baby was delivered stillborn as a result of contracting oral bacteria from her mum, who was suffering from gum disease.
Experts have long suspected there is a link between bacteria in the mouth and miscarriage but they believe this to be the first recorded case of oral bacteria causing the death of an almost full term baby.
The mum, who had the common gum disease gingivitis during pregnancy, gave birth to a stillborn baby at 39 weeks. The doctors found the same oral bacteria that was in the mum's mouth also in the baby's bloodstream, lungs and stomach.
According to the British Dental Foundation, hormonal changes in pregnancy make mums-to-be more susceptible to gum disease and gingivitis is thought to affect thousands of pregnant women.
"This case has shown that improving oral healthcare amongst pregnant women can have a significant impact on an unborn baby," said Dr Nigel Carter, chief executive of the British Dental Health Foundation.
NHS dental treatment is free during pregnancy and for 12 months after you've given birth. To claim for dental treatment, tick a box on a form provided by the dentist or show your Exemption Certificate.