US scientists have found a strong link between the success of gum disease treatment and the likelihood of giving birth prematurely, according to new research published in BJOG: An International Journal of Obstetrics and Gynaecology.
There are a number of factors such as low body mass index, alcohol consumption and smoking which are associated with an increased rate of preterm birth. More recently researchers have reported that oral infection may also be associated with such an increase.
This study looked at 322 pregnant women who all had gum disease. The group was split into two groups; one group received scaling and root planning - cleaning above and below the gum-line - and oral hygiene instruction while the other group only received oral hygiene instruction.
The incidence of preterm birth was high in both the treatment group and the untreated group; 52.4% of the women in the untreated control group had a preterm baby compared with 45.6% in the treatment group. These differences were not statistically significant.
However, the researchers then looked at whether the success of treatment was associated with the rate of preterm birth. The women were examined 20 weeks after the initial treatment and success was characterized by reduced inflammation and no increase in loosening of the teeth.
Within the treatment group of 160 women, 49 women were classed as having successful gum treatment and only four had a preterm baby (8%). In comparison, 111 women had unsuccessful treatment and 69 of these (62%) had preterm babies. These differences are highly statistically significant.
The results show that pregnant women who were resistant to scaling and root planning were significantly more likely to deliver preterm babies than those where it was successful.
The mean age of the women in the study was 23.7 years, 87.5% were African-American and 90% had not seen a dentist for tooth cleaning.
Marjorie Jeffcoat , Professor of Periodontology at the University of Pennsylvania and lead author of the paper, explained: "Our research group is very excited about these results. First these data show that pregnant women can receive periodontal treatment safely in order to improve their oral health. Second in a high risk group of pregnant women, such as those patients who participated in this study, successful periodontal treatment, when rendered as an adjunct to conventional obstetric care, may reduce the incidence of preterm birth. Future papers will address the role of antimicrobial mouth rinses in reducing the incidence of preterm birth."
Professor Philip Steer, BJOG editor-in-chief, said: "Researchers have previously suggested that severe gum infections cause an increase in the production of prostaglandin and tumour necrosis factor, chemicals which are associated with preterm labour. This new study shows a strong link between unsuccessful gum disease treatment and preterm birth.
"However, we need to bear in mind that 69% of women failed to respond to the dental treatment given. Therefore more effective treatment will need to be devised before we can be sure that successful treatment improves outcome, rather than simply being a marker of pregnancies with a lower background level of inflammation that will go to term anyway.
"It is important that pregnant women are given advice on dental treatment, however it is also important to note that there are many other causes of preterm birth that should also be tackled, such as smoking, excess alcohol consumption and obesity."