title: Periodontal disease and spontaneous preterm birth: a case control study.
abstract: BACKGROUND
  Several studies have suggested an association between periodontal disease and prematurity but this finding has not been consistently observed.
  
  
  METHODS
  Case control study. Cases (n = 50) were women who had delivered after spontaneous preterm labor at <35 weeks gestation. Two groups of controls (n = 101) were recruited: women who were undelivered but at a preterm gestation and women who delivered at term. A standard, clinical, periodontal examination was performed and gingival crevicular fluid was obtained from standardized locations and tested for neutrophil elastase along with the bacterial enzymes gingipain and dipeptidylpeptidase. Data were analyzed with Fisher's exact tests, ANOVA and multivariate logistic regression.
  
  
  RESULTS
  There was no difference in the proportion of sites with significant attachment loss (> or =3 mm): Cases-3.2%, Controls-2.2% p = 0.21. The gingival crevicular fluid concentrations of elastase and gingipain were elevated in cases vs. controls 238.8 uU/ul vs. 159.6 uU/ul p = .007 and 2.70 uU/ul vs. 1.56 uU/ul p = .001. On multivariate analysis, the mean log concentration of elastase, but not of gingipain, remained a significant predictor of preterm labor p = .0.015.
  
  
  CONCLUSIONS
  We found no evidence that clinical periodontal disease is associated with spontaneous preterm birth. Elevated gingival crevicular fluid levels of elastase were associated with preterm birth but further research is needed before this can be assumed to be a causal relationship.
authors.affiliation: Department of Obstetrics and Gynecology, Foothills Hospital, 1403 29th St, NW, Calgary, Alberta, T2N 2T9, Canada. stephen.wood@calgaryhealthregion.ca
authors.forename: Stephen
authors.initials: S
authors.lastname: Wood
authors.forename: Albert
authors.initials: A
authors.lastname: Frydman
authors.forename: Stephen
authors.initials: S
authors.lastname: Cox
authors.forename: Rollin
authors.initials: R
authors.lastname: Brant
authors.forename: Sheilia
authors.initials: S
authors.lastname: Needoba
authors.forename: Barry
authors.initials: B
authors.lastname: Eley
authors.forename: Reg
authors.initials: R
authors.lastname: Sauve