Diagnostic criteria for APS

Clinical and laboratory criteria for antiphospholipid syndrome

At least one clinical and one laboratory criterion must be must be present for diagnosis:-

Category Criteria


      • ≥ 1 episodes of arterial, venous or small vessel thrombosis, OR

Pregnancy morbidity

    • ≥ 1 unexplained deaths of a morphologically-normal fetus at or beyond week 10 of gestation, OR
    • ≥ 1 pre-term births of a morphologically normal neonate before week 34 of gestation because of: (i) eclampsia or severe pre-eclampsia, OR (ii) recognized features of placental insufficiency , OR
    • ≥ 3 unexplained consecutive spontaneous miscarriages before week 10 of gestation, provided maternal anatomic or hormonal abnormalities and paternal and maternal chromosomal causes are excluded
  1. Lupus anticoagulant present in plasma, on ≥ 2 occasions ≥ 12 weeks apart, OR
  2. Anticardiolipin antibody of IgG and/or IgM isotype in serum or plasma, present in medium or high titre (> 40GPL units or MPL units, or > the 99th centile), on ≥ 2 occasions, ≥ 12 weeks apart, OR
  3. Anti-b2–glycoprotein I antibody of IgG and/or IgM isotype in serum or plasma (titre > 99th centile), present on ≥ 2 occasions ≥ 12 weeks apart



  1. Miyakis S, Lockshin MD, Atsumi T, Branch DW, Brey RL, Cervera R et al. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J Thromb Haemost 2006; 4: 295–306
  2. Asherson RA, Cervera R, de Groot PG, Erkan D, Boffa MC, Piette JC st al. Catastrophic antiphospholipid syndrome: international consensus statement on classification criteria and treatment guidelines. Lupus 2003; 12: 530–4