Maternal Periodontal Disease and Preterm or Extreme Preterm Birth: An Ordinal Logistic Regression Analysis

Background: Despite previous studies addressing the link between preterm or low birth weight infants and maternal periodontitis, extreme preterm births have received far less attention. This study is designed to address the possible association between maternal periodontal disease and preterm or extreme preterm birth. Methods: Immediately after childbirth, 1,207 women underwent an examination in which periodontal disease was assessed according to two alternative definitions: 1) four or more teeth with at least one site showing probing depth (PD) >= 4 mm and clinical attachment loss (AL) >= 3 mm, and 2) at least one site showing PD and clinical AL >= 4 mm. For each of these definitions, two types of multivariate analysis were conducted: a linear regression analysis for the number of gestation weeks, and a more specific ordinal logistic regression analysis for the ordinal variable gestation time categorized as normal (term) (n = 1,046 women) or mild moderate (n = 146 women) or extreme preterm (n = 15 women). Results: Periodontal disease was associated with fewer weeks of gestation by linear regression (definition 1: P = 0.012; definition 2: P<0.001) and with preterm (n = 161; mild-moderate and extreme) or extreme preterm births (n = 15) by ordinal logistic regression (definition 1: odds ratio [OR] = 1.83, 95% confidence interval [CI]: 1.28 to 2.62; definition 2: OR = 2.37, 95% CI: 1.62 to 3.46). Conclusion: Our findings suggest that periodontal disease is associated with a premature or extremely premature birth. J Periodontol 2010;81:350-358.