Periodontal disease and preterm birth: Findings from the 2015 Pelotas birth cohort study

Abstract Objectives To verify the association between periodontal conditions and preterm birth. Materials and methods This study used data from the 2015 Pelotas Birth Cohort Study, Brazil. Pregnant women expected to give birth in 2015 were interviewed and dentally examined by a trained dentist, with periodontal measures collected in all teeth, six sites per tooth. Exposure was periodontal disease. Outcomes were preterm birth (all births <37 weeks of gestational age) and early preterm birth (<34 weeks). Analysis was carried out using Poisson regression according to a directed acyclic graph. Results A total of 2,474 women participated in the study. Incidence of preterm births was 10.2% and of early preterm births was 3.5%. Frequency of gingivitis was 21.7%, and periodontitis was 14.9%. Periodontitis was associated with a risk almost two times higher of having early preterm delivery compared with healthy pregnant women (RR 1.93; 95% CI 1.09–3.43). Presence of 5+ mm periodontal pocket with bleeding on probing was also associated with higher risk for early preterm delivery. Conclusions The association between periodontal disease in pregnancy and the occurrence of preterm delivery is sensitive to the case definitions. Periodontal disease increased the risk of early preterm delivery.