Table 2.

Periodontal pathogens associated with adverse pregnancy outcomes.

Author, Year	Study Design	Sample	Periodontal Pathogens	Conclusions
Buduneli et al., 2005 [12]	Case–control	Humans	P. gingivalis, P. intermedia, P. nigrescens, A.A, Streptococcus intermedius, F. nucleatum, Peptostreptococcus micros, C. rectus, Eikenella corrodens, Selenomonas noxia, and S. intermedius	P. micros and C. rectus were associated with PLBW.
Garcia et al., 2019 [50]	Case–control	Animals	F. nucleatum	Omega-3 fatty acids suppress inflammatory responses elicited by bacteria, making them potentially effective in reducing adverse pregnancy outcomes.
Han et al., 2010 [51]	Case report	Animals	F. nucleatum	F. nucleatum can translocate from the oral to the uterine environment.
Han et al., 2004 [52]	Case–control	Animals	F. nucleatum	The hematologic transmission capabilities of F. nucleatum could induce adverse pregnancy outcomes.
Chopra et al., 2020 [53] Reyes et al., 2017 [54]	Review	N/A	P. gingivalis	The pathogenesis of P. gingivalis is associated with adverse pregnancy outcomes: -Maternal/fetal tissue alterations via the action of virulence factors, surface adhesion molecules, and enzymes; -Enhanced production of cytokines, oxidative stresses, and acute-phase proteins; -Elevated fetal adrenal cortisol levels.
Ao M et al., 2017 [55]		Animals	P. gingivalis	-The LPS of P. gingivalis was capable of pro-inflammatory cytokine upregulation; -Translocation capabilities of P. gingivalis in utero.
Lin et al., 2007 [49]	Case–control	Humans	P. gingivalis, Tannerella forsythia, Prevotella intermedia, and Prevotella nigrescens, A.A	-Statistically significant higher levels of all bacteria associated with preterm births in comparison with full-term births; -A 2.4-fold increase in levels of A.A bacteria in preterm deliveries as the pregnancy progresses until after birth when compared with full-term deliveries.