Asociación entre enfermedad periodontal materna y complicaciones del embarazoun análisis de regresión logística ordinal para el pretérmino, extremo pretérmino, bajo peso y muy bajo peso al nacer

Abstract

Periodontitis is a disease of bacterial origin that arises from an unbalanced response between host immune system and microorganisms from dental biofilm. It is characterized by the inflammation of periodontal tissues and loss of clinical attachment. On the other hand, adverse pregnancy outcomes, that are Preterm Birth and Low Birth Weight, are the most important factors related to neonatal morbidity and mortality, and can lead to severe newborn complications such as respiratory problems, blinding disorders, neurological sequelae or problems of neurological development. Studies regarding the potential association between both of these events have emerged in the beginning of the 90’s. Such association was based on the possibility that systemic dissemination of inflammatory mediators, bacterial products, or periodontal pathogens could represent a potential risk factor for adverse pregnancy outcomes. Nevertheless, even though many studies have been conducted, no uniformity in the results could be observed. This lack of uniformity could be related to different methodologies, sample sizes, definitions used to define the events under investigation, and the presence of common risk factors such as smoking and socioeconomic status. In addition, few studies have focused on Extreme Preterm Birth and it is important to highlight that no previous reports regarding Very Low Birth Weight have been found in the literature. Therefore, after considering the previous studies in this field, and taking into consideration the need for new approaches to clarify the potential relationship between maternal periodontitis and adverse pregnancy outcomes, the main goal of the present study was to evaluate the potential association between maternal periodontal disease and Preterm Birth, Extreme Preterm Birth, Low Birth Weight, and Very Low Birth Weight, by means of an Ordinal Logistic Regression statistical analysis. For this purpose, a cross-sectional study was conducted in a public hospital in Belo Horizonte City (Brazil). A total of 1265 women were evaluated in the immediate post partum through applying two of the most commonly used diagnostic criteria for periodontal disease definition: Criterion 1 (López et al., J Dent Res. 81(1):58-63, 2002; López et al., J Periodontol. 73(8):911-924, 2002) - presence of 4 or more teeth with at least one site with Probing Depth (PD) ≥ 4 mm and Clinical Attachment Loss (CAL) ≥ 3 mm; and Criterion 2 (Albandar, J Periodontol. 78:1179-1181, 2007) – at least one interproximal site with PD and CAL ≥ 4 mm. Subsequently, sample was divided in groups as following: Control (n=1046), Mild to Moderate Preterm Birth (n=146), Extreme Preterm birth (n=15), Low Birth Weight (n=145), and Very Low Birth Weight (n=15). In relation to the statistical analysis, a descriptive and bivariate analysis was initially performed for each study group. Afterwards, for each periodontitis diagnostic criterion, two multivariate analyses were performed, taking into consideration other sociodemographic risk factors, deleterious habits, maternal health and obstetric factors. The first analysis included a Linear Regression for Gestational Age (weeks) and Birth Weight (grams). The second and more specific analysis included an Ordinal Logistic Regression for an ordinal variable composed by Control, Preterm Birth (n=161) and Extreme Preterm Birth (n=15) groups, as well as Control, Low Birth Weight (n=160) and Very Low Birth Weight (n=15) groups. Findings from the present study indicated that maternal periodontitis was associated with a decrease in the mean number of Gestational Weeks (through Linear Regression analysis), and with Preterm Birth and Extreme Preterm Birth (through Ordinal Logistic Regression), presenting Odds Ratios (ORs) of 1.83 and 2.37 for Criteria 1 and 2, respectively. On the other hand, Periodontal Disease was associated with a decrease in the mean Birth Weight through Linear Regression, and with Low and Very Low Birth Weight through Ordinal Logistic Regression, presenting ORs of 1.65 for Low Birth Weight when using Criterion 1, and of 2.0 for Low Birth Weight and Very Low Birth Weight when using Criterion 2. It is also important stress that the association with maternal periodontal disease was more evident among cases of Preterm Birth and Extreme Preterm Birth, since higher and more significant OR rates were observed. In the same manner, results of diagnostic Criterion 2 were more evident and significant for Gestational Age than for Birth Weight. Besides the association with maternal periodontal disease, Preterm Birth / Extreme Preterm Birth and Low birth / Very Low Birth Weight were also associated with the following variables: extremes of Maternal Age, low Educational level, previous Preterm Births, number of Prenatal visits, Primiparity, the interaction between these last two variables, and the effect of the interaction between single Marital Status and the presence of Genitourinary Infection. The main conclusion of the present study is that peridontitis was associated with either Preterm Birth or Extreme Preterm Birth, as well as Low Birth Weight and Very Low Birth Weight. However, in order to clarify as much as possible these associations, further studies are needed, specially considering both Extreme Preterm Birth and Very Low Birth Weight, but counting for it with as high as possible sample sizes, given their low prevalence.