A 29-year-old woman, gravida 3 para 2, at 36 weeks gestation presented to the emergency department with complaints of sudden-onset severe abdominal pain, heavy vaginal bleeding, and decreased fetal movements. Her pregnancy had been uneventful until this episode. She had been exposed to extreme temperatures due to outdoor living during the last ten days. Three days ago, she went to an urgent care center for a severe cough and was prescribed azithromycin for ‘possible bronchitis’. On arrival, she appeared pale, diaphoretic, and visibly distressed. Her temperature is 102 °F , heart rate is 122 beats/min, blood pressure is 90/60 mm Hg, respirations are 34 breaths/min, and oxygen saturation is 89% on room air. On examination, the abdomen was firm and tender to palpation, with a rigid uterus. A bedside ultrasound revealed a retroplacental clot and partial detachment of the placenta. Fetal heart monitoring showed late decelerations and minimal variability. Laboratory results Platelet count: 53,000/μL (normal range: 150,000–450,000/μL) Prothrombin time (PT): 18 seconds (normal range: 10–13 seconds) Activated partial thromboplastin time (aPTT): 40 seconds (normal range: 25–35 seconds) Fibrinogen: 100 mg/dL (normal range: 200–400 mg/dL) D-dimer: >10,000 ng/mL (normal range: <500 ng/mL) Fibrin degradation products (FDPs): 40 µg/mL (normal range: <5 µg/mL) Hemoglobin: 8.5 g/dL ( normal range: 12–16 g/dL for women) Peripheral blood smear: Schistocytes Which of the following could have triggered this condition in this patient?
