Modulation of Lipopolysaccharide-Induced Chorioamnionitis in Fetal Sheep by Maternal Betamethasone.

Objective: Wetestedthehypothesisthattheorderofexposuretomaternalbetamethasoneandintra-amniotic(IA)lipo- polysaccharide(LPS)willdifferentiallymodulateinflammationinthechorioamnion. StudyDesign: Time-matedMerinoewes withsingletonfetusesreceivedsalinealone,IALPSalone,maternalbetamethasonebeforeLPS,orbetamethasoneafterLPS. Weassessedinflammatorymarkersinthechorioamnionandtheamnioticfluid. Results: Inflammatorycellinfiltration, expressionofmyeloperoxidase,serumamyloidA3(acutephasereactant)inthechorioamnion,andlevelsofinterleukin(IL)-8in theamnioticfluidincreased7daysafterLPSexposure.BetamethasonepriortoLPSdecreasedinfiltrationoftheinflammatory cells,CD3+Tcells,anddecreasedthelevelsofIL-1ß andIL-8intheamnioticfluid.Conclusions:Betamethasone7dayspriorto LPSexposuresuppressedLPS-inducedinflammation.Themarkersofinflammationlargelyhadreturnedtothebaseline14days afterLPSexposure. [ABSTRACT FROM AUTHOR]