CCL2 and gingivitis: First, the release of pro-inflammatory chemokines, like IL-1, IL-6, IL-8, TNF-α or PGE2 into the systemic bloodstream may reach the feta-placental unit and induce adverse pregnancy outcomes.27, 30 Specifically, interleukin-1 has been shown to induce preterm delivery.27 Furthermore, the induction of gingivitis in healthy individuals has been shown to increase acute systemic inflammation and associated levels of CRP, IL-6, MCP-1 and the activation of monocytes, which were reversible by adequate OH.10