Maternal mortality from systemic illness: unraveling the contribution of the immune response.

Objective: Maternal morbidity and/or mortality (MM) is increased in pyelonephritis and influenza. Alterations in the immune response could account for the increase MM. We sought to determine whether the immune response is functionally different during pregnant and nonpregnant (NP) states.

Study Design: Mouse model of systemic and localized inflammation was used. Maternal serum was assessed for expression of T-helper cell type 1 and 2 cytokines. Maternal spleens were harvested for immunohistochemistry.

Results: Systemic administration of lipopolysaccharides resulted in no mortality to NP mice compared with 88% in preterm and 100% in term mice. A potent cytokine response was present in both NP and pregnancy. Systemic inflammation in pregnancy results in increased CD8 and CD11c expression in spleens.

Conclusion: Differences in cytokine response to systemic inflammation is unlikley to modulate the increased MM during pregnancy. Altered T-cell and dendritic cell responses in pregnancy may be responsible for the increase in MM.