 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. 