TNF and periodontal disorder: As Offenbacher indicated in 1996, these inflammatory mediators (IL-1β, PGE2, TNF-α, and IL-6) are directly related to the pathogenesis of periodontal disease (1), and although IL-1β, PGE2, and TNF-α levels naturally increase as pregnancy approaches the third trimester, exaggerated increases have been associated with various adverse pregnancy outcomes, especially preterm birth (12).