Do the clinical criteria used to diagnose periodontitis affect the association with prematurity?

In recent years, several studies have examined the possible relationship between periodontal disease in pregnant women and preterm birth. One of the difficulties facing these studies is the heterogeneity of the clinical criteria used to define periodontitis. The aim of this cross-sectional study was to determine the degree of association between maternal periodontitis and preterm birth according to different consensus definitions of periodontal disease. In a study of 146 mothers (60 with preterm births and 86 with term deliveries) at the Sant Joan de Déu Maternal and Children’s Hospital in Barcelona, a periodontal examination was carried out within 2 days of birth and the presence of periodontal disease was evaluated using the main clinical classifications published in the literature. The prevalence of periodontitis ranged from 25.4 to 52.1%, depending on the criteria used for its definition. Using the most restrictive criteria, pregnant women with periodontitis had a higher risk of preterm birth (OR: 7.49; p < 0.001) and premature rupture of membranes (OR: 2.49; p = 0.017). Premature infants born to mothers with periodontitis presented a tendency toward low weight, adjusted for gestational age (OR: 3.32; p = 0.065). Our findings suggest that the association between periodontitis and preterm birth is influenced by the definitions of periodontitis used.