Table 2.

Definition of antiphospholipid syndrome

A. Clinical criteria:  1. Vascular thrombosis: one or more arterial, venous or small vessel thrombosis  2. Pregnancy morbidity   One or more fetal death at or beyond 10 weeks of gestation   One or more premature births before 34th week of gestation because of eclampsia or placental insufficiency   Three or more embryonic losses before 10 weeks of gestation

B. Laboratory criteria (titers should be positive on 2 occasions at least 12 weeks apart)  1. Lupus anticoagulant  2. Anticardiolipin antibody IgG or IgM at a medium or high titer (> 40)  3. B2 glycoprotein antibody IgG or IgM in medium or high titer (over 99th percentile)

Diagnosis requires at least one of the two clinical and one of the three laboratory criteria