Periodontal disease and pregnancy outcome: significance of the association in relation to the periodontal disease definition. A case control study

Maternal periodontitis has been suggested as one of the risk factors for preterm birth (PTB) and low birth weight (LBW) infants. The aim of this study was to explore whether the application of three different definitions of periodontal disease had an influence on the significance of the association between pregnancy outcome and periodontitis in a group of new mothers. Material and method: 410 puerperas were interviewed and examined within one week from the delivery. Data about socioeconomic status, risk factors, oral health status were collected via questionnaire, and a full mouth dental and periodontal examination was performed according to WHO guidelines. In this study we used three different definitions of periodontal disease: (1) we have established three different levels of periodontitis (level 1 = 100% of the sites probed with CAL <4 mm, level 2 = at least one site with 4 mm <CAL <5mm, Levels 3 = at least one site with CAL> 6mm). We decided to define a person with periodontal disease (PD) when at least one site had a CAL> 4 mm. (2) Secondly, we considered a definition of periodontal disease reported in the international literature that used the criteria of extent and severity of 3:60. Periodontal disease was established for subjects with at least 60% of the sites probed with CAL> 3mm. (3) Finally we used the criteria of extension and severity 4:20 (at least 20% of the sites probed with CAL> 4mm). We have considered as “case” all patients with adverse pregnancy outcome (PTB, LBW or PLBW) and as “control” those patients with term pregnancy and infant weight> 2500g. A univariate analysis was performed for the three definitions of periodontitis (PD, Extent 3: 60, Extent 4:20) and pregnancy outcome. Results: The prevalence of adverse pregnancy outcomes were as follows: PTB 6,6 %, LBW 2,9 %, and PLBW 10,5 %. No statistically significant differences were found between case and control groups using PD (p=0,96, Pearson test), extent 3:60 (p= 0,64, Pearson test) and extent 4:20 periodontitis definitions (p= 0,75, Pearson test). Conclusions: Although the three different criteria to detect periodontal disease accounted for different prevalence, our findings failed to demonstrate a possible association between periodontal disease and adverse pregnancy outcomes