IADR Abstract Archives
The Association Between Fusobacterium nucleatum subspecies and Adverse Pregnancy Outcomes
Fusobacterium nucleatum (Fn) is one of the most abundant species in the sub-gingival biofilm and has been isolated from amniotic fluid in cases of adverse pregnancy outcomes (APO). The aim of the study was to identify if particular sub-species of Fn were capable of haematogenous transmission to the uterus in mice causing APO.
Methods:
At day 16 of their 21 day gestation, pregnant mice were intravenously injected with 0.1 mL saline or individual Fn subspecies. At day 18, two mice were sacrificed to identify if Fn was present in the blood, liver, spleen or placenta using PCR. DNA primers used were specific for each subspecies.
Results:
The haematogenous spread of Fn to the placenta was confirmed. Mice challenged with Fn demonstrated intrauterine growth restriction (IUGR), low birth weight (LBW) and fetal resorption compared with controls. The litter size and number of resorptions were statistically significant between groups, (p=0.023 and p=0.001 respectively). Mice inoculated with;
a) subsp. vincentii and fusiforme demonstrated significantly more resorptions than controls (mean difference 3.30, p=0.014, p=.026).
b) subsp. nucleatum demonstrated late resorptions associated with arrested fetal development.
c) subsp. fusiforme significantly reduced placental weight (0.089±SEM g versus 0.114±SEMg p=0.00).
d) subsp. polymorphum was the only subspecies found not to translocate to the placenta.
e) subsp. vincentii reduced the length of gestation (19.6± 0.173 days) compared with other groups (p=0.025).
f) Fn subsp. induced a significant difference in weight at day 18 and delivery compared with controls.
Conclusions:
This study confirmed that Fn can transmigrate haematogenously to the uterus, leading to APO in mice. The introduction of Fn subsp. into the bloodstream results in IUGR, LBW and stillbirth to varying degrees. Fn subsp. vincentii may be associated with PTB. This study strengthens the role of Fn in the association between periodontitis and adverse pregnancy outcomes.