Abstract
Anti β2-GPI antibody is one of antiphospholipid antibody(APA)and this antibody bins to protein (β2-GPI)which binds to phospholipid. Recently many pathogenic mechanism concerning about APA were discovered APAs cause not only intravascular coagulation but also activation of endothelial cells and placental trophoblast. The premature delivery caused by severe preeclampsia,eclampsia and placental dysfunction is included in the criteria of antiphospholipid syndrome. In cases of APS during pregnancy, adequate care and treatment should be done for not only thrombosis but also placental dysfunction relate to villous damage.