Which mechanism describes the indirect effect of inflammatory mediators on adverse pregnancy outcomes?

• A. FIRST mechanism to explain the relationship between periodontal disease & adverse pregnancy outcomes
• B. SECOND mechanism to explain the relationship between periodontal disease & adverse pregnancy outcomes
• C. Physiologic induction of labor
• D. Direct translocation of pathogens to the feto-placental unit

Answer: (B)

Periodontal infection triggers local inflammation that spills over into the systemic circulation. The body releases inflammatory mediators such as interleukins, tumor necrosis factor, and prostaglandins (like PGE2 and PGF2α). Once these mediators reach gestational tissues, they can stimulate cervical ripening and uterine contractions, and they promote enzymatic changes that weaken fetal membranes. This indirect, inflammatory pathway can lead to adverse outcomes such as preterm birth and low birth weight even if the pathogens themselves don’t invade the feto-placental unit. In contrast, direct invasion by bacteria into the fetal environment represents a different mechanism, but the question focuses on the indirect effect mediated by the maternal inflammatory response.