The relationship between periodontal disease and preterm low birthweight: clinical and microbiological results

Findings on the effect of periodontal disease on preterm low birthweight are inconclusive. The objective of this study was to compare periodontal clinical measures and the levels and proportions of 39 bacterial species in subgingival biofilm samples in puerperal women with preterm low birthweight and nonpreterm low birthweight. A case-control study with 116 postpartum women over 30 years of age was conducted. Four case groups of subjects with preterm and/or low birthweight [preterm (n = 40), low birthweight (n = 35), preterm and/or low birthweight (n = 50) and preterm and low birthweight (n = 25)] were compared with normal nonpreterm low-birthweight controls (n = 66). Periodontal clinical parameters of dental plaque, calculus, bleeding on probing, periodontal pocket depth and clinical attachment level were recorded. Covariates included socio-demographic and anthropometric characteristics, smoking, alcohol consumption, obstetric history, prenatal care and diseases during pregnancy. Two subgingival biofilm samples per women were analyzed for 39 bacterial species using a checkerboard DNA-DNA hybridization technique. The mean periodontal pocket depth was significantly higher in nonpreterm low-birthweight controls than in subjects in the preterm low birthweight, preterm and/or low birthweight, and preterm and low-birthweight groups. Clinical attachment level measures were not different between all pairs of cases and control groups. Groups did not differ with respect to the mean proportions of different microbial complexes. The mean counts of Treponema socranskii were lower in all case groups compared with the control group. Maternal periodontal microbiota and clinical characteristics of periodontal disease were not associated with having preterm low-birthweight babies.