Stillbirths With Placental Hemorrhagic Endovasculitis: A Morphologic Assessment With Clinical Implications

Abstract Context.—Hemorrhagic endovasculitis (HEV) is a vasodisruptive alteration affecting fetal-placental blood vessels of all calibers. Hemorrhagic endovasculitis is found in association with stillbirth and abnormalities of growth and development in livebirths. The role of HEV in the pathogenesis of these conditions is not known. Objective.—To further understand these events, we compare clinicopathologic features of HEV-affected placentas from stillbirths with those from livebirth pregnancies. Additionally, we assess the relationship of morphologic forms of HEV to clinical events and time of fetal death in utero and evaluate the significance of extensive versus localized HEV lesions in placentas of stillbirths. Design.—We reviewed the clinical records and slides from 119 stillbirths with placentas affected by HEV classified above a specified severity level (cases) and 119 matched stillbirths with placentas not affected by HEV (controls). A subset of 21 stillbirth placentas exhibiting focal HEV lesions ...