Antiphospholipid syndrome (APS) is defined as an autoimmune disorder characterized by recurrent thrombosis or obstetrical morbidity. These features are linked to the presence in blood of autoantibodies against negatively charged phospholipids or phospholipid-binding proteins. Obstetric morbidity includes recurrent abortion (early and late) and severe pre-eclampsia (P-EC)/hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome, and/or severe placental insufficiency. Criteria that define the major clinical and laboratory events were published in revised forms in the Sydney recommendations in 2006. We analyzed the blood of patients with severe P-EC according to the subgroups based on the 2006 revised criteria definition and compared these results with women after uncomplicated pregnancy and delivery. We found 20% elevated antiphospholipid antibodies (APAs) in women with severe P-EC (group I, 7.5%; group IIa, 5.0%; group IIb, 5.0%; group IIc, 2.5%). The increased APAs were observed only in women with severe P-EC (odds ratio: 2.45; 95% confidence interval, 1.01 to 4.3) and not in patients with severe P-EC at> 34 weeks of gestation. According to our retrospective observation, we recommend the determination of anticardiolipin antibodies, lupus anticoagulant, and β-2 glycoprotein-1 antibodies in patients with severe P-EC at< 34 weeks of gestation.