The rates of preterm birth across the developed world have not fallen despite many research studies that have aimed to reduce the risk of early labour or other complications of pregnancy. Many of these studies have focused on treating infections in the vagina, as we have good information that there are signs of inflammation in the uterus in at least two thirds of pregnancies resulting in very early birth. These studies however have not been effective, indicating that in general, antibiotics have little ability to prevent prematurity.

WIRF researchers are now investigating the possibility that the source of that inflammation in the uterus may be from a distant site, the gums. Infection and inflammation of the gums is known as periodontal disease, and does not respond to the antibiotic treatments that have been used to attempt to prevent preterm birth. Fifteen percent of adult Australians have periodontal disease, and most are unaware of the affliction.

Pilot studies conducted in the laboratory and in the clinics at KEMH have provided evidence that this link between the gums and the pregnant uterus is worthy of further investigation.

A large randomized controlled trial of the treatment of the periodontal disease during pregnancy commenced in March 2005. More than five thousand women between 12 and 20 weeks of pregnancy are being screened by a simple examination performed by a research dental hygienist.

One thousand women with periodontal disease will then be invited to participate. Each is then allocated at random to receive periodontal treatment in mid-pregnancy, or when the pregnancy is completed.

The treatment is mechanical, and consists of removal of dental plaque and instruction in oral health care. The treatment for each woman, if priced at standard government rates, would be in excess of $1000. The study will take three years to complete and will provide definitive information on whether treatment of periodontal disease during pregnancy is of benefit.

This project is funded by NHMRC and is a collaborative effort between the UWA School of Women’s and Infants’ Health, WIRF, the UWA School of Dentistry and the Oral Health Centre of Western Australia.