A 32-year-old primigravida at 32 weeks presents with BP 158/106 mmHg, proteinuria 3.4 g/24 hours, and platelet count 78,000/µL. LDH is 720 IU/L, AST 95 IU/L, and peripheral smear shows schistocytes. Which of the following pathophysiological mechanisms BEST explains the thrombocytopenia in this condition?

• A Immune-mediated platelet destruction via anti-platelet IgG antibodies
• B Microangiopathic platelet consumption due to widespread endothelial activation and fibrin deposition ✓
• C Bone marrow suppression secondary to hepatic ischemia
• D Dilutional thrombocytopenia from expanded plasma volume

Explanation

This patient has HELLP syndrome. The thrombocytopenia in HELLP results from platelet activation and consumption at sites of endothelial damage — activated endothelium triggers platelet aggregation and microthrombus formation within small vessels, a process of microangiopathic hemolysis rather than immune destruction or dilution. Anti-platelet antibodies are the mechanism in ITP, and dilution occurs early in normal pregnancy but does not cause counts below 100,000/µL. Bone marrow suppression would also affect other cell lines uniformly.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.