Periodontopathogenic microbiota, infectious mechanisms and preterm birth: analysis with structural equations (cohort—BRISA)

Purpose The association between periodontopathogenic microbiota and preterm birth (PTB) has been overly studied. However, the biological mechanisms involved are little known. The objective is to evaluate the effect of periodontopathogenic bacteria burden (PBB), periodontal disease and other infections during pregnancy on preterm birth (PTB), through Structural Equation Modeling. Methods This was a case–control study nested in a prospective cohort called BRISA, including 330 pregnant women, 110 cases and 220 controls. This study included the following variables: cytokines interleukin-10 (IL-10) and transforming growth factor beta (TGF-β), periodontal disease, PBB, age, socioeconomic status (SES), systemic infections and PTB. The correlations between variables were analyzed using Standardized Coefficient (SC). Results Greater PBB interfered positively with the occurrence of periodontal disease (SC: 0.027; p : 0.011), but these were not associated with the cytokines studied, nor with PTB. The lower serum levels of IL-10 (SC − 0.330; p 0.022) and TGF-β (SC − 0.612; p