465 Histologic chorioamnionitis in pregnancies complicated by preeclampsia and the effect on neonatal outcomes

Abstract

Inflammation plays a major role in the development of preeclampsia. Histological chorioamnionitis (HC) is a common placental finding, that can represent acute or chronic inflammation and can influence neonatal outcomes. We aimed to examine the added effect of HC on neonatal outcomes in pregnancies complicated by preeclampsia. The computerized medical files of all pregnancies with the diagnosis of preeclampsia at 24-42 weeks of gestation between 2008 and 2019 were reviewed. Cases with overt clinical chorioamnionitis were excluded. Placental lesions were classified according to “Amsterdam” criteria. The composite adverse neonatal outcome included ≥ 1 of the following: Apgar at 5 min < 7, respiratory support, respiratory distress syndrome (RDS), neurological morbidity, NEC, sepsis, or death. The maternal and neonatal outcomes were compared between cases of preeclampsia with and without HC. Multivariable regression analysis was performed to identify independent associations with adverse neonatal outcomes. As compared to the preeclampsia without HC group (n=517), the preeclampsia with HC group (n=55) was characterized by a more advanced gestational age (GA) at delivery (37.7±3.4 vs. 36.13.3 weeks, p<0.001), and a lower rate of a history of previous preeclampsia (p=0.04). Neonates in the preeclampsia with HC group had a higher rate of composite adverse neonatal outcome (p<0.001) despite a higher mean birth weight (p=0.005)- Table 1. By multivariate analysis, HC was found to be independently associated with adverse neonatal-outcome (aOR 1.33, 95% CI 1.11-3.09)- Table 2. In placental pathology preeclampsia without HC was associated with a higher rate of MVM lesions (p=0.01) – the "classical" placental findings of preeclampsia. In pregnancies complicated by preeclampsia concomitant placental HC was associated with a higher rate of adverse neonatal outcome despite a more advanced GA at delivery. This inflammatory mechanism plays a role in a subgroup of preeclampsia cases, causing an additional risk for the developing fetus.View Large Image Figure ViewerDownload Hi-res image Download (PPT)