Saving Lives at Birth: Primary Prevention of Periodontal Disease in Relation to Preterm Birth in Malawi

Significance and Impact: Adverse birth outcomes related to the length of gestation (preterm birth) are recognized as one of the most significant disorders in maternal-child health at a global scale. In the developed world, the preterm birth rate approximates 7%. In Malawi, the investigators have recently demonstrated that this rate more than triples to approximate 26.1%. Of the 4 million newborn deaths annually, nearly 1/3 (27%) are directly attributable to prematurity with another 36% secondary to related opportunistic infections (sepsis, pneumonia, gastrointestinal). 75% of the 4 million deaths occur within the first week of life, with the vast majority occurring in the first 48 hours. For those that do survive, there are persistent and lifelong risks due to stunted growth, chronic infection, retinopathy of prematurity, and bronchopulmonary dysplasia. The link between maternal oral health (periodontal disease in particular) and risk of preterm birth has been demonstrated across all populations (rural and urban, in both industrialized and developing regions) studied to date. However, in multiple randomized controlled trials treatment of active periodontal disease with scaling and planning during pregnancy has failed to demonstrate a significant benefit in preventing preterm birth. Why would maternal oral health impact preterm birth? In rodents, subcutaneous inoculations with periodontal pathogens cause dose-dependent decreases in pup weights, and elicit inflammatory responses that can trigger preterm birth when present in amniotic fluid. Periodontitis (defined as a destructive inflammation of the periodontium) has a prevalence of 30% or greater in women of child bearing age. By definition, it involves microbial infiltration of the periodontium, which stimulates a chronic inflammatory response, recurrent bacteremia, and the production of cytokines and prostaglandins which trigger risk of preterm birth. It is the same production of prostaglandins which are felt to mediate the risk of preterm birth. So if the investigators know that there is biologic evidence that periodontitis is related to preterm birth, but treating active periodontitis does not reduce these morbidities, is it possible that preventing periodontitis might prevent preterm birth and low birth weight? If so, what are the least expensive efficacious preventative measures? The investigators' overarching hypothesis is that comprehensive primary preterm birth prevention, inclusive of maternal oral health with xylitol chewing gum (the intervention), will reduce the rate of periodontal disease and caries, preterm birth prevalence, and neonatal mortality.