Preeclampsia (PE) is characterized by disturbed extravillous trophoblast migration toward uterine spiral arteries leading to increased uteroplacental vascular resistance and by vascular dysfunction resulting in reduced systemic vasodilatory properties. Its pathogenesis is mediated by an altered bioavailability of nitric oxide (NO) and tissue damage caused by increased levels of reactive oxygen species (ROS). Furthermore, superoxide (O2−) rapidly inactivates NO and forms peroxynitrite (ONOO−). It is known that ONOO− accumulates in the placental tissues and injures the placental function in PE. In addition, ROS could stimulate platelet adhesion and aggregation leading to intravascular coagulopathy. ROS-induced coagulopathy causes placental infarction and impairs the uteroplacental blood flow in PE. The disorders could lead to the reduction of oxygen and nutrients required for normal fetal development resulting in fetal growth restriction. On the other hand, several antioxidants scavenge ROS and protect tissues against oxidative damage. Placental antioxidants including catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) protect the vasculature from ROS and maintain the vascular function. However, placental ischemia in PE decreases the antioxidant activity resulting in further elevated oxidative stress, which leads to the appearance of the pathological conditions of PE including hypertension and proteinuria. Oxidative stress is defined as an imbalance between ROS and antioxidant activity. This review provides new insights about roles of oxidative stress in the pathophysiology of PE.

The present findings suggest that NO and ROS play important roles in the pathogenesis of preeclampsia and that these roles involve Ang II.

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Aim The purpose of this study was to report the 3‐year experience of a nationwide demonstration project to introduce non‐invasive prenatal testing (NIPT) of maternal plasma for aneuploidy, and review the current status of NIPT in Japan. Methods Tests were conducted to detect aneuploidy in high‐risk pregnant women, and adequate genetic counseling was provided. The clinical data, test results, and pregnancy outcomes were recorded. We discuss the problems of NIPT on the basis of published reports and meta‐analyses. Results From April 2013 to March 2016, 30 613 tests were conducted at 55 medical sites participating in a multicenter clinical study. Among the 30 613 women tested, 554 were positive (1.81%) and 30 021 were negative (98.1%) for aneuploidy. Of the 289, 128, and 44 women who tested positive for trisomies 21, 18, and 13, respectively, and underwent definitive testing, 279 (96.5%), 106 (82.8%), and 28 (63.6%) were determined to have a true‐positive result. For the 13 481 women with negative result and whose progress could be traced, two had a false‐negative result (0.02%). The tests were performed on the condition that a standard level of genetic counseling be provided at hospitals. Conclusion Here, we report on the 3‐year nationwide experience with NIPT in Japan. It is important to establish a genetic counseling system to enable women to make informed decisions regarding prenatal testing. Moreover, a welfare system is warranted to support women who decide to give birth to and raise children with chromosomal diseases.

In PE, some factors including Ang II and TNF-alpha stimulated EPC proliferation; however, the impairment of EPC mobilization into systemic circulation by serum factors may contribute to insufficient regeneration of EC in disturbed utero-placental circulation of PE.