Successful treatment of advanced gum disease in pregnant women may significantly reduce the risk of preterm birth, according to new research.

Periodontal disease is a severe form of gum disease that damages the underlying bone that holds teeth in place. Previous research had identified maternal periodontal disease as a risk factor for preterm births (at less than 35 weeks).

Dentists and doctors in the US collaborated on a study of 322 expectant mothers. The mums-to-be were divided into two groups: those who did and those who did not receive periodontal treatment. All of the women received oral hygiene instructions from a dental hygienist, as well as home care supplies (toothbrushes, dental floss, and fluoride toothpaste). Those in the untreated group received no further periodontal treatment as part of the study.

The periodontal treatment group received dental scaling and root planing (SRP) from a hygienist before the end of the first trimester. SRP consists of cleaning above and below the gum-line, and is the same care a patient would expect to receive from a dental hygienist or a dentist in general practice.

Mechanical treatment alone was offered, as the most common antibiotic therapies used to treat periodontal disease employ tetracyclines, which are contraindicated in pregnant women because they permanently stain the baby’s teeth.

Researchers found that those women whose disease was successfully treated were six times more likely to carry their baby to full term.

The authors recommended that pregnant women with periodontal disease should be offered conservative periodontal therapy, as it is safe and, if successful, can reduce the incidence of spontaneous preterm birth.

The research was published online in September in the British Journal of Gynaecology.