Beyond HELLP: An Unusual Cause of Severe Thrombocytopenia in Pregnancy.

Thrombotic thrombocytopenic purpura (TTP) is a rare yet potentially fatal thrombotic microangiopathy that poses significant risks during pregnancy. It is characterized by microangiopathic hemolytic anemia, profound thrombocytopenia, and widespread microvascular thrombosis. We present a case of pregnancy-associated TTP presenting with isolated severe thrombocytopenia, highlighting the diagnostic challenge. A 27-year-old, G3P1 woman at 31+6 weeks of gestation presented with hypogastric pain and a resolved episode of vomiting. Laboratory evaluation revealed severe thrombocytopenia (platelets: 9 × 10⁹/L), mild anemia, and proteinuria. Differential diagnosis included immune thrombocytopenic purpura (ITP), HELLP (hemolysis, elevated liver enzymes, and low platelet count), and TTP. Initial therapy included corticosteroids, platelet transfusions, primarily suspecting ITP as the first differential diagnosis, and magnesium sulfate later after lactate dehydrogenase levels were suggestive of hemolysis. HELLP syndrome being the main differential, counseling was done about the possible need for preterm delivery, and a neonatologist was involved for discussion with the parents. This was followed by urgent ADAMTS13 testing, which confirmed TTP. The patient was transferred to a tertiary care center for plasma exchange therapy, which improved the platelet count. She subsequently underwent induction of labor at 35 weeks for severe preeclampsia, delivering vaginally with postpartum hemorrhage (1.7 L) managed with transfusions. Both maternal and neonatal outcomes were favorable, and both were discharged on day 10 of delivery. This case illustrates the atypical presentation of TTP, where severe thrombocytopenia may occur without classic neurological or renal symptoms. Timely recognition of the correct diagnosis allowed appropriate treatment and prevented unnecessary very preterm delivery.