A 30-year-old pregnant woman at 36 weeks gestation presents to the emergency department with sudden onset severe abdominal pain, vaginal bleeding, and signs of fetal distress. Her blood pressure is 80/50 mmHg, and she is tachycardic. Laboratory tests reveal hemoglobin 8.5 g/dL, platelet count 60,000/µL, PT 25 seconds (control 12 seconds), aPTT 60 seconds (control 30 seconds), and markedly elevated D-dimer. Peripheral blood smear shows schistocytes. Which of the following is the most likely diagnosis?

Explanation

The clinical presentation (pregnant woman with sudden abdominal pain and vaginal bleeding, suggesting placental abruption, a known trigger for DIC) combined with the laboratory findings (thrombocytopenia, prolonged PT and aPTT, elevated D-dimer, and schistocytes) is highly characteristic of Disseminated Intravascular Coagulation (DIC). ITP typically presents with isolated thrombocytopenia and normal coagulation times. TTP also presents with thrombocytopenia and schistocytes but usually has normal coagulation times and no significant bleeding diathesis from factor consumption. Hemophilia A is a congenital deficiency of Factor VIII, leading to prolonged aPTT but normal PT, platelet count, and D-dimer.