The Periodontal Disease as a Risk Factor for Preterm Birth and Low Birth Weight: A Review of Case-Control Studies

Abstract

Background: There are numerous risk factors known that can negatively affect the pregnancy outcomes and it was shown that pregnant women suffering from periodontitis (an inflammation of the supporting tissues around the teeth) were at a higher risk of delivering a preterm low birth weight infant. The aim of this study was to summarize the results of case-control studies conducted up to December 2007 which concerned the relationship between periodontal disease and adverse pregnancy outcomes (low birth weight and/or preterm birth). Methods: A literature search of the PubMed was conducted up to December 2007 covering the articles which discussed the periodontal disease as a risk factor for low birth weight (LBW) and/or preterm birth (PTB). Only case-control studies were included in this review according to specific criteria. Preterm birth was defined as delivery at fewer than 37 completed weeks' gestation, and low birth weight as delivery of an infant with a birth weight under 2500 g. Results: Of the 862 papers identified, 25 analytical case-control studies which investigated the relationship between the periodontal disease and (PTB) or (LBW), considering the disease to be or not to be a risk factor, met the inclusion criteria. There was a clear heterogeneity between studies concerning measurement of periodontal disease and selection of type of adverse pregnancy outcome. Most studies did not control for confounders, thus raising serious doubts about their conclusions. The methodological limitations of most studies did not allow conclusions concerning the effects of periodontal disease on adverse pregnancy outcomes. Conclusions: The relationship between periodontal diseases and pregnancy outcomes is still to date a controversial issue because of the discrepancy of the results collected. Moreover, little is still known about the subgingival changes of the microflora in pregnant women and their possible role in raising the ability of disordering the pregnancy outcomes.