**3.2 Non-thrombotic mechanisms**

The non-thrombotic mechanism which leads to defective placentation are thought to be the main cause of obstetric manifestations. Especially, aPLs have direct effect on trophoblast viability and syncytialization as well as on trophoblast invasion and alter the production of syncyotrophoblast hormones. Moreover, signs of inflammation within the decidua, such as fibrin deposits, were more represented than thrombosis in histological analysis of placenta from women with APS, suggesting another mechanism in pregnancies affected by aPL [52, 53].
