Characteristics of histopathological and ultrastructural features of placental villi in pregnant Nepalese women

The placenta is an important functional unit for gas transfer between mother and fetus. The placental membrane, consisting of trophoblast layer interposed between maternal and fetal blood, plays an active role for intensity of respiration, but no morphological evidence has been documented. Until now, it has been reported that fetal growth retardation and increased fetal mortality rate usually could be seen at high altitude. In an attempt to find the cause of high perinatal mortality rate in Nepal, this study was undertaken to examine pathologically about 1000 Himalayan placentas obtained in Nepal and Tibet since 1977, and the results were compared with those of 5500 Japanese placentas at Saitama Medical School since 1990. In this study, characteristics of ultrastructural features of the Nepalese placental villi investigated in recent years are reported. (1) The gross characteristics of placental pathology in the Himalayan group were represented by marked subchorionic fibrin deposits and increased chorionic cysts in contrast to low incidence of intervillous thrombosis compared with those of the Japanese group. (2) As characteristics of histological findings of the placental villi between Himalayan and Japanese groups, the incidence of chorangiosis and chorangioma in the Himalayan group was significantly higher than that in the Japanese group. (3) Accompanying an increase of vasculosyncytial membrane (VSM) in the villi, thickness and separation of basement membrane of the syncytium in addition to increased apoptosis of syncytial cell nuclei were recognized. (4) As characteristic ultrastructural features of chorionic villi of Nepalese placentas, an increase of mitochondria and cystic formation of rough endoplasmic reticulum (rER), in addition to appearance of lamellar bodies similar to alveolar epithelial type II cell in organellae of the syncytium, were observed. These ultrastructural changes of the placental villous capillaries may be ascribed to hypevascularization caused by the chronic hypoxic state. It is, therefore, presumed that trophoblast cells may play an important role for gas transfer mecha-nism under such a hypoxic state at high altitude.     

绒毛膜血管病对新生儿的影响：450例临床分析

目的 研究母亲胎盘病理绒毛膜血管病对新生儿病死率和并发症发生率的影响。方法 回顾性分析2016年7月至2020年2月厦门市妇幼保健院新生儿科生后3 d内住院的患儿,根据母亲胎盘病理是否提示绒毛膜血管病分为观察组和对照组,各450例。分析两组患儿的一般情况、母亲妊娠期合并症、新生儿病死率和新生儿并发症的发生率。结果 观察组剖宫产率高于对照组（P < 0.05）,观察组母亲妊娠高血压发生率高于对照组（P < 0.05）。与对照组相比,观察组患儿先天结构畸形、小于胎龄儿、低Apgar评分发生率更高（P < 0.05）;观察组患儿病死率、脑损伤发生率、早产儿视网膜病及宫外生长发育迟缓的发生率均更高（P < 0.05）。结论 母亲胎盘病理绒毛膜血管病的新生儿病死率更高,并发症发生率更高,需提高对绒毛膜血管病的认识,尽早干预,减少并发症,改善预后。     

Chorangiosis: report of three cases and review of the literature

The vascular lesions in the placenta form a heterogeneous group of possibly interrelated alterations.

Gestational age distribution is different for chorangioma, chorangiosis, and chorangiomatosis; the pathogenesis is unclear, and histological features, especially those of chorangiosis and chorangiomatosis, frequently overlap.

Chorangiomatosis shows intermediate features between chorangiosis and chorangioma. In this lesion, particularly when multifocal, the presence of small capillaries is similar to chorangiosis, but the gestational age is different from both chorangiosis and chorangioma.

We present three cases of chorangiosis examined during one-year routine pathological analysis of placental tissue and report the histological, histochemical, and immunohistochemical features. Furthermore, we go into the difficulty of discerning the villous capillary lesions and the utility of this division, and describe the clinical effects of these lesions on fetal outcome.     

Clinico-pathological profile of 12 cases of chorangiosis

Chorangiosis is one of the vascular lesions that involvs terminal chorionic villi. It is commonly associated with various feto-maternal conditions like pre-eclampsia, diabetes etc. However, the clinical significance of this pathological finding has not been studied extensively. The aim of this study was to identify the various conditions associated with chorangiosis and to determine its clinical significance. A retrospective study to identify the cases of placentas diagnosed with chorangiosis was carried out and the clinical and morphological details of these cases were reviewed. Immunostaining for CD34 and muscle-specific actin was also performed to confirm chorangiosis and to exclude chorangiomatosis. A total of 12 cases of chorangiosis were retrieved, most of them were of term gestation. Five of these 12 cases were associated with various maternal conditions including syphilis (2 cases) and single cases of pre-eclampsia, diabetes and jaundice. One case in each had abruptio placenta and non-immune hydrops. Of these 12 cases, seven were stillborn. Microscopically, all 12 cases showed extensive chorangiosis involving terminal villi. In addition, two cases showed focal infarction and one had extensive calcification. Immunostaining for CD34 confirmed increased number of capillaries while muscle-specific actin was negative, excluding chorangiomatosis. The clinico-pathological profile presented in this study suggests that chorangiosis has characteristic pathological features for its recognition and needs to be differentiated from similar conditions like chorangioma and chorangiomatosis. Also, chorangiosis has potential clinical significance and should be mentioned in the pathology report and the patient should be investigated for associated conditions like syphilis, pre-eclampsia, diabetes etc.     

Fetal and maternal vascular lesions

Many commonly diagnosed disorders of the placenta relate to maternal and fetal blood flow and are thus common in the placentas of infants with adverse perinatal outcomes. Severe uteroplacental vascular disease may lead to extensive placental infarction and villous changes of reduced uteroplacental blood flow, a morphologic feature commonly associated with intrauterine growth restriction and fetal demise. Lesser degrees of villous change are seen in many infants with premature delivery, term, and multiple births resulting in admission to the neonatal intensive care units. Fetal vascular lesions including chorangiosis and fetal thrombotic vasculopathy are two processes that appear to be associated with increased risk of poor outcome.     

Chorangiosis: the potential role of smoking and air pollution

Chorangiosis is considered to be strongly associated with various fetal, maternal, and placental disorders, including pre-eclampsia, diabetes, hypertension, and major congenital anomalies, and has been found to correlate with increased fetal morbidity and mortality. In this study, we investigated the pathologic effects of maternal smoking and air pollution on the pathogenesis of chorangiosis. We investigated 92 placentas macroscopically and microscopically over a 3-month period (March 2006-May 2006) at Denizli State Hospital to identify the frequency of chorangiosis and the potential role of maternal smoking and air pollution. Placental changes were examined by light microscopy after hematoxylin and eosin (H&E) staining and immunohistochemical evaluation of CD 34 and CD 68; muscle-specific actin was used to confirm the diagnosis. Among the 92 mothers included in the study, 33 were smokers (group I), 31 were thought to have been exposed to air pollution (group II), and 28 were living in rural areas free of air pollution and maternal smoking (group III). Chorangiosis was found in 14% (13/92) of all placentas: 7 (53.8%) cases were assigned to group I, 5 (38.5%) to group II, and 1 (7.7%) to group III. Vascular changes were found mainly in the smoking and air pollution groups. There appeared to be no correlation of these vascular changes with placental weight, parity, gestational age, major congenital anomalies, and maternal factors, including diabetes and pre-eclampsia. We presume that smoking and air pollution may contribute to the development of chorangiosis. We suggest that chorangiosis may be an adaptive response to maternal hypoxia, and studies addressing the role of smoking and air pollution in chorangiosis may provide new insights into the pathogenesis of this condition.