Can oral anaerobic bacteria cause adverse pregnancy outcomes?

AIM Maternal periodontal infection has been recognized as a risk factor for premature and low birthweight infants. It is suspected that pathogens causing periodontal disease may translocate to the amniotic cavity and so contribute to triggering an adverse pregnancy outcome. The aim of this study was to evaluate whether the presence of specific periodontal pathogens may influence the incidence of preterm labor and premature birth. MATERIAL AND METHODS This study was designed as a hospital-based case-control study. A total of 70 pregnant women, aged 18-40 with single live pregnancy were recruited from the Departement of Gynecolgy and Obstetrics at a General hospital in Sibenik, Croatia, between March 2013 to March 2014. The case group: 30 pregnant women who were hospitalised with signs of premature labor. CONTROL GROUP 40 patients with normal pregnancy post-delivery up to 48 hrs, who had given birth at term, and the baby had a weight of more than 2500 gr. These women had undergone microbiological examination at the time of recruitment, microbial samples, paper point subgingival swabs were obtained in both groups and processed by anaerobic culturing. Standard procedures were used for culture and identification of bacteria. Information was collected on demographics, health behaviors, and obstetric and systemic diseases that may have influence the premature delivery. RESULTS The levels of periodontal pathogens tended to be higher in the premature (case group) labor compared to the term deliveries (control group). Levels of Porphyromonas gingivalis, Fuscobacterium nucleatum, Actinomyces actinomycetecomitans were statistically significantly higher in premature births as compared to term deliveries, adjusting for baseline levels. The joint effects of red and orange microbial clusters were significantly higher in the premature group compared to the term group. CONCLUSIONS The study shows a significant association betwen periodontal anaerobic infection and adverse pregnancy outcome. High levels of periodontal pathogens during pregnancy are associated with an increased risk for preterm delivery. Further studies elucidating the role of the microbial load and maternal immune response as related to pregnancy outcome seem merited.