Periodontitis, a marker of risk in pregnancy for preterm birth

Abstract

Why chronic periodontitis may induce an inflammatory response with premature pregnancy termination is unclear. (1) To assess if periodontitis predicts premature gestation; (2) to study amniotic fluid cytokines and periodontitis variables in early-stage pregnancy. A periodontal examination and collection of amniotic fluid was performed (weeks 15-20) of pregnancy in 36 women at risk for pregnancy complications. Amniotic fluid (bacteria), vaginal smears and intra-oral plaque samples were studied. Cytokine levels in amniotic fluid were studied in relation to other study variables. Periodontitis was diagnosed in 20% of normal and in 83% of preterm birth cases (p<0.01). Bacteria were never found in the amniotic fluids studied. Sub-gingival plaque samples including bacteria in the orange and red complexes were found in 18% of full-term 100% of preterm cases (p<0.001) and total colony-forming units (CFUs) were higher in preterm birth (p<0.01). Amniotic levels of interleukin (IL)-6 and prostaglandin-E2 (PGE2) were higher in preterm cases (p<0.001). Amniotic IL-6 (r=0.56, p<0.01) and PGE2 (r=0.50, p<0.01) cytokine levels were correlated with CFU from sub-gingival plaque samples (r2=0.44). The odds ratio of preterm delivery and having periodontitis was 20.0 (95% confidence interval (CI): 2.0-201.7, p<0.01). The odds of >60 CFU in sub-gingival plaque and preterm birth was 32.5:1 (95% CI: 3.0-335.1, p<01). Pregnant women with findings of elevated amniotic fluid levels of PGE2, IL-6 and IL-8 in the 15-20 weeks of pregnancy and with periodontitis are at high risk for premature birth. The implication of this is that periodontitis can induce a primary host response in the chorioamnion leading to preterm birth.