title: Persistently high levels of periodontal pathogens associated with preterm pregnancy outcome.
abstract: BACKGROUND
  Few studies examining the association between periodontal diseases and preterm birth have explored the underlying microbial and antibody responses associated with oral infection.
  
  
  METHODS
  A nested case-control study was performed using data from a recent interventional trial following the delayed-treatment control group of 31 subjects with periodontal diseases. The levels of eight oral bacteria and the maternal immunoglobulin G (IgG) responses in serum to these bacteria were measured at antepartum and postpartum visits to determine the relationship to cases (preterm delivery <37 weeks' gestation) and controls (term delivery).
  
  
  RESULTS
  Antepartum, the levels of periodontal pathogens tended to be higher in the preterm (case group) deliveries compared to the term deliveries (control group). Maternal anti-Porphyromonas gingivalis IgG was significantly lower in the preterm group compared to the term group (P = 0.028). Postpartum, levels of P. gingivalis, Tannerella forsythia, Prevotella intermedia, and Prevotella nigrescens were statistically significantly higher in preterm births compared to term deliveries, adjusting for baseline levels. The joint effects of red and orange microbial clusters were significantly higher in the preterm group compared to the term group.
  
  
  CONCLUSIONS
  High levels of periodontal pathogens and low maternal IgG antibody response to periodontal bacteria during pregnancy are associated with an increased risk for preterm delivery. Further studies elucidating the role of the microbial load and maternal immune response as related to pregnancy outcome seem merited.
authors.affiliation: Center for Oral and Systemic Diseases, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7455, USA.
authors.forename: Dongming
authors.initials: D
authors.lastname: Lin
authors.forename: Kevin
authors.initials: K
authors.lastname: Moss
authors.forename: James D
authors.initials: JD
authors.lastname: Beck
authors.forename: Arthur
authors.initials: A
authors.lastname: Hefti
authors.forename: Steven
authors.initials: S
authors.lastname: Offenbacher
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000917:Antibody Formation / Q000276:immunology; D001438:Bacteroidaceae / Q000276:immunology / Q000302:isolation & purification; D016022:Case-Control Studies; D003773:Dental Plaque / Q000382:microbiology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008137:Longitudinal Studies; D010518:Periodontitis / Q000097:blood / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D010865:Pilot Projects; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood* / Q000276:immunology / Q000382:microbiology; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000097:blood* / Q000276:immunology / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G