Both Acute and Chronic Placental Inflammation Are Overrepresented in Term Stillbirths: A Case-Control Study

Objective. To elucidate differences in the frequency and severity of acute chorioamnionitis (CAM) and chronic villitis in placentas from stillborns compared with liveborns at term and to evaluate other risk factors and placental findings. Design. Case-control study. Setting. All delivery wards in major Stockholm area. Population or Sample. Placentas from stillborn/case (n = 126) and liveborn/control (n = 273) neonates were prospectively collected between 2002 and 2005. Methods. CAM was assessed on a three-grade scale based on the presence and distribution of polymorphonuclear leucocytes in the chorion/amnion. The presence of vasculitis and funisitis was recorded separately. Chronic villitis was diagnosed by the presence of mononuclear cells in the villous stroma. Relevant clinical data were collected from a specially constructed, web-based database. The statistic analyses were performed using multivariable logistic regression. Results. CAM (especially severe, AOR: 7.39 CI: 3.05–17.95), villous immaturity (AOR: 7.17 CI: 2.66–19.33), villitis (<1 % AOR: 4.31 CI: 1.16–15.98; ≥1 %, AOR: 3.87 CI: 1.38–10.83), SGA (AOR: 7.52 CI: 3.06–18.48), and BMI >24.9 (AOR: 2.06 CI: 1.21–3.51) were all connected to an elevated risk of term stillbirth. Conclusions. We found that CAM, chronic villitis, villous immaturity, SGA, and maternal overweight, but not vasculitis or funisitis are independently associated with risk for stillbirth at term.