IL6 and periodontitis: Sert et al. [5], evaluated the levels of serum IL-1β, IL-6, TNF-α, IL-10, VEGF, PLGF, and sVEGFR-1, and − 2 in the association between periodontal disease and adverse pregnancy outcomes; according to their results, there were no significant differences in the serum PLGF level between health, gingivitis, and periodontitis, which is also pointing at the inconsistencies of the role of PLGF for a definitive conclusion.