Table 1.

Classification Criteria for Antiphospholipid Syndrome [1]

APS is present if 1 of the clinical criteria and 1 of the laboratory criteria are met

Clinical criteria	1. Vascular thrombosis	≥1 clinical episode of arterial, venous, or small-vessel thrombosis.
	2. Pregnancy morbidity	≥1 unexplained death of a morphologically normal fetus at ≥10 weeks of gestation ≥1 premature delivery of a morphologically normal fetus at <34 weeks gestation because of: Severe pre-eclampsia or eclampsia defined according to standard definition Recognized features of placental insufficiency ≥3 unexplained consecutive miscarriages at <10 weeks gestation, with maternal and paternal factors (anatomic, hormonal or chromosomal abnormalities) excluded
Laboratory criteria	The presence of antiphospholipid antibodies on ≥2 occasions ≥12 weeks apart: Presence of lupus anticoagulant in plasma Medium- to high-titer anticardiolipin antibodies of IgG or IgM isoforms Medium- to high-titer anti-beta-2 glycoprotein-I (anti-β2GPI) antibodies of IgG or IgM isoforms