Criteria developed at the University of Mississippi, as of 2006: "For a patient to merit a diagnosis of HELLP syndrome, class 1 requires severe thrombocytopenia (platelets ≤50,000/μl), evidence of hepatic dysfunction (AST and/or ALT ≥70 IU/l), and evidence suggestive of hemolysis (total serum LDH ≥600 IU/l); class 2 requires similar criteria except thrombocytopenia is moderate (>50,000 to ≤100,000/μl); and class 3 includes patients with mild thrombocytopenia (platelets >100,000 but ≤150,000/μl), mild hepatic dysfunction (AST and/or ALT ≥40 IU/l), and hemolysis (total serum LDH ≥600 IU/L).