Miscarriage and pre-eclampsia are the most common disorders of human pregnancy. Both are placental-related and exceptional in other mammalian species. Ultrasound imaging has enabled events during early pregnancy to be visualized in vivo for the first time. As a result, a new understanding of the early materno-fetal relationship has emerged and, with it, new insight into the pathogenesis of these disorders. Unifying the two is the concept of placental oxidative stress, with associated necrosis and apoptosis of the trophoblastic epithelium of the placental villous tree. In normal pregnancies, the earliest stages of development take place in a low oxygen (O2) environment. This physiological hypoxia of the early gestational sac protects the developing fetus against the deleterious and teratogenic effects of O2 free radicals (OFRs). In miscarriage, development of the placento-decidual interface is severely impaired leading to early and widespread onset of maternal blood flow and major oxidative degeneration. This mechanism is common to all miscarriages, with the time at which it occurs in the first trimester depending on the aetiology. In contrast, in pre-eclampsia the trophoblastic invasion is sufficient to allow early pregnancy phases of placentation but too shallow for complete transformation of the arterial utero-placental circulation, predisposing to a repetitive ischaemia-reperfusion (I/R) phenomenon. We suggest that pre-eclampsia is a three-stage disorder with the primary pathology being an excessive or atypical maternal immune response. This would impair the placentation process leading to chronic oxidative stress in the placenta and finally to diffuse maternal endothelial cell dysfunction.

中文翻译：

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妊娠胎盘相关疾病：氧化应激的参与及其对人类进化的影响。

流产和先兆子痫是人类妊娠期最常见的疾病。两者都与胎盘相关，并且在其他哺乳动物物种中是特殊的。超声成像首次使怀孕早期的事件在体内可视化。因此，人们对早期母婴关系有了新的认识，随之而来的是对这些疾病发病机制的新见解。将两者统一起来的是胎盘氧化应激的概念，与胎盘绒毛树滋养层上皮的坏死和凋亡相关。在正常妊娠中，发育的最早阶段发生在低氧 (O2) 环境中。早期孕囊的生理性缺氧可以保护发育中的胎儿免受 O2 自由基 (OFR) 的有害和致畸作用。在流产中，胎盘-蜕膜界面的发育严重受损，导致母体血流早期和广泛发生以及主要的氧化变性。这种机制对于所有流产都很常见，其发生在妊娠早期的时间取决于流产的病因。相反，在先兆子痫中，滋养层细胞的侵入足以允许胎盘在妊娠早期阶段形成，但对于动脉子宫胎盘循环的完全转变来说太浅，容易出现重复性缺血再灌注（I/R）现象。我们认为先兆子痫是一种三阶段性疾病，其主要病理是过度或非典型的母体免疫反应。这将损害胎盘形成过程，导致胎盘中的慢性氧化应激，并最终导致弥漫性母体内皮细胞功能障碍。