Thrombotic thrombocytopenic purpura masquerading as hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome in late pregnancy.

Background: Thrombotic thrombocytopenic purpura rarely presents during late pregnancy or immediately postpartum. This report describes the clinical course of a patient considered to have hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome but later determined to have thrombotic thrombocytopenic purpura.

Methods: At 37 weeks of gestation, a multiparous woman was diagnosed with HELLP syndrome. She received high-dose dexamethasone, magnesium, antihypertensives, and platelets before delivery. Over the next 36 hours, renal function acutely worsened and death ensued. One week after death a plasma ADAMTS13 activity of 4% was reported.

Conclusions: Thrombotic thrombocytopenic purpura can mimic HELLP syndrome late in gestation. Lack of response to dexamethasone within 12-24 hours and atypical relationships among laboratory values are two clues that thrombotic thrombocytopenic purpura may be the underlying pathology and that plasma exchange is emergently needed.