Placental Findings in Preterm and Term Preeclampsia: An Integrative Review of the Literature

Abstract Introduction Preeclampsia (PE) is a pregnancy complication associated with increased maternal and perinatal morbidity and mortality. The disease presents with recent onset hypertension (after 20 weeks of gestation) and proteinuria, and can progress to multiple organ dysfunction, with worse outcomes among early onset preeclampsia (EOP) cases (<34 weeks). The placenta is considered the root cause of PE; it represents the interface between the mother and the fetus, and acts as a macromembrane between the two circulations, due to its villous and vascular structures. Therefore, in pathological conditions, macroscopic and microscopic evaluation can provide clinically useful information that can confirm diagnosis and enlighten about outcomes and future therapeutic benefit. Objective To perform an integrative review of the literature on pathological placental findings associated to preeclampsia (comparing EOP and late onset preeclampsia [LOP]) and its impacts on clinical manifestations. Results: Cases of EOP presented worse maternal and perinatal outcomes, and pathophysiological and anatomopathological findings were different between EOP and LOP placentas, with less placental perfusion, greater placental pathological changes with less villous volume (villous hypoplasia), greater amount of trophoblastic debris, syncytial nodules, microcalcification, villous infarcts, decidual arteriolopathy in EOP placentas when compared with LOP placentas. Clinically, the use of low doses of aspirin has been shown to be effective in preventing PE, as well asmagnesium sulfate in preventing seizures in cases of severe features. Conclusion The anatomopathological characteristics between EOP and LOP are significantly different, with large morphological changes in cases of EOP, such as

摘要 引言
子痫前期（preeclampsia, PE）是一类妊娠并发症，可显著升高孕产妇及围产期的发病率与死亡率。该病以妊娠20周后新发高血压伴蛋白尿为核心临床表现，可进展为多器官功能障碍，其中早发型子痫前期（early onset preeclampsia, EOP，妊娠<34周）患者的预后更差。胎盘被认为是PE的发病根源：它作为母胎之间的交换界面，依托自身绒毛与血管结构，成为分隔母胎循环的大分子屏障。因此在病理状态下，对胎盘进行大体及显微镜下评估，可获取具有临床价值的信息，辅助明确诊断、阐明预后及指导后续治疗获益。
研究目的
本研究旨在针对与子痫前期相关的胎盘病理表现（对比早发型子痫前期EOP与晚发型子痫前期late onset preeclampsia, LOP）及其对临床表现的影响开展整合性文献综述。
研究结果
EOP患者的孕产妇及围产期预后更差；EOP与LOP胎盘的病理生理及解剖病理特征存在显著差异：与LOP胎盘相比，EOP胎盘的灌注水平更低，病理改变更显著，具体表现为绒毛体积更小（绒毛发育不全）、滋养细胞碎屑更多、合体结节、微钙化、绒毛梗死及蜕膜小动脉病程度更重。临床层面，小剂量阿司匹林已被证实可有效预防PE，硫酸镁则可预防重症患者的子痫发作。
结论
EOP与LOP的解剖病理特征存在显著差异，EOP患者存在更为显著的形态学改变，例如