Fibrinoid necrosis and atherosis of vessels in decidua capsularis of fetal membrane roll.

OBJECTIVE: The purpose of this study was to evaluate the frequency of maternal vasculopathy and to determine the usefulness of placental examination in correlation with clinical manifestation of pregnancy-induced hypertension. STUDY DESIGN: We investigated 350 pregnancy-induced hypertension placentas over a 2.5-year period (January 2002-June 2004) to identify the potential usefulness of the maternal vasculopathy in histologic diagnosis and corroboration of clinical preeclampsia. This study was carried out at West Virginia University Ruby Memorial Hospital, where 1271 placentas were examined macroscopically and microscopically for the period. The presence or absence of vascular changes, infarctions, thrombosis, abruption, chorangiosis, and chorioamnionitis were investigated for each placenta with the clinical diagnosis of preeclampsia or pregnancy-induced hypertension. RESULTS: Two types of vascular changes that are characteristic of pregnancy-induced hypertension, namely maternal atherosis and fibrinoid medial necrosis, were found in 21.4% of the placentas (75/350 placentas). These vascular changes were found mainly in the decidua capsularis of the membrane rolls, not on the decidua basalis of the maternal floor. There were more placental infarctions within these placentas (32.3%; 113/350 placentas). Intervillous thrombosis was 18.9% (66/350 placentas); microscopic abruption was 6.3% (22/350 placentas); chorangiosis was 10.9% (38/350 placentas), and chorioamnionitis was 8.6% (30/350 placentas). CONCLUSION: These findings demonstrate that the maternal vascular changes that are characteristic of pregnancy-induced hypertension are found in approximately 1 of 5 pregnancy-induced hypertension placentas. Examination of pregnancy-induced hypertension placentas should be based on a combination of a number of histologic changes. Furthermore, the decidua capsularis of the fetal membrane roll, rather than the decidua basalis of the maternal floor, of the placenta should be examined for these maternal vascular changes.

Zhang P, Schmidt M, Cook L. Maternal vasculopathy and histologic diagnosis of preeclampsia: poor correlation of histologic changes and clinical manifestation. Am J Obstet Gynecol. 2006 Apr;194(4):1050-6.