A 38-year-old woman at 30 weeks and 5 days of gestation presented to the emergency department with sudden, severe left flank pain, accompanied by chills and dysuria. Examination revealed left costovertebral angle tenderness, while the abdomen was soft and non-tender. Initial laboratory tests and FAST scan were unremarkable, and she was transferred to the labor and delivery unit with stable vital signs. Approximately 20 minutes later, fetal monitoring showed recurrent deep variable decelerations, followed by progressive fetal bradycardia. The cervix was closed, long, and posterior. Concurrently, the patient's blood pressure declined from 90/40 to 80/30 mm Hg despite intravenous fluids, oxygen, repositioning, and vasopressor support.

She subsequently developed chest pain, worsening hypotension, and altered consciousness. The differential diagnosis included pulmonary embolism, pyelonephritis, and rapidly progressive sepsis. Despite escalating resuscitation, her blood pressure reached 60/30 mm Hg, necessitating intubation and ICU transfer. At 3:36 pm, she suffered cardiac arrest, prompting CPR. A perimortem cesarean section was performed three minutes later, with the neonate having Apgar scores of 0 at 1 and 5 minutes. During abdominal entry, extensive hemoperitoneum with clots was identified, and the bleeding source was found to be a ruptured splenic artery aneurysm. Massive transfusion was initiated, followed by splenectomy, correction of coagulopathy, and temporary abdominal closure.