Periodontitis and risk of preterm birth and low birthweight - a meta-analysis

Introduction: Periodontitis and prematurity are social diseases with common risk factors. In 1996 periodontitis was proven to be a possible significant and independent risk factor of preterm birth of newborns with low body weight. Numerous studies on the influence of periodontitis on the time of birth and/or birth weight of newborns have been conducted throughout the world since, including several ones in Poland, but their results have been inconsistent. Work objective: A meta-analysis of case-control, prospective and cohort studies on the influence of periodontitis on preterm birth and low birth weight. Methods: The international and Polish bibliography bases were searched for essays on the relationship between periodontitis and preterm birth and/or low birth weight published between 1996 and 2010. All essays qualified for the meta-analysis were subjected to qualitative evaluation. The calculation of the overall odds ratio used both, fixed-effects and random-effects models (DerSimonian-Liard method). The heterogeneity of the included studies and effect of publication bias were also subjected to evaluation. Results: The meta-analysis included 15 case-control studies, 1 cross-sectional study and 6 cohort studies. The essays came from 4 continents: 8 from Europe (including 2 from Poland), 7 from South America, 4 from North. America, and 3 from Asia. The total analysis covered 12047 pregnant women. The overall odds ratio of giving premature birth to a child with low weight for mothers with periodontitis in the model of random effects amounted to 2.35 (1.88-2.93, p<0.0001). For low birth weight, the overall OR was 1.5 (95% CI: 1.26-1.79, p=0.001) for premature births - 2.73 (95% CI: 2.06-3.6, p<0.0001). A significant heterogeneity of the studies included in the meta-analysis was observed, and a significant publication bias was also demonstrated. Conclusions: The hypothesis of periodontitis as an independent risk factor of preterm birth and/or low birth weight needs further verification. In order to achieve that, it is necessary to conduct more methodologically well-planned cohort and intervention studies. The need of dental care for pregnant women as an integral component of the prenatal care program remains to be an important issue.