Publisher Summary This chapter focuses on the classification and prevalence of
antiphospholipid syndrome (APS) in the general population. The classification criteria for the
APS were revised at the international consensus meeting at Sapparo, Japan. The new
criteria include two clinical outcomes, which include thrombosis either arterial, venous, or
vasculopathic; and pregnancy morbidity, either recurrent early (< 10 week) losses, one or
more late fetal losses, or preterm birth due to severe placental insufficiency or pre …