Segmental arterial mediolysis leading to spontaneous rupture of splenic artery and fatal hemorrhage in pregnancy.

We report an unexpected death of a 22-year-old primigravida who was admitted to the hospital with sudden abdominal pain two days before a scheduled delivery. During an emergency caesarean section due to intrauterine asphyxia, intraabdominal bleeding was observed with no apparent source of bleeding. Newly formed blood clots in the subdiaphragmatic space and arterial bleeding near the splenic hilum required a surgery on the next day. Hemorrhagic shock led to multiple organ failure on the fourth day of admission. The autopsy revealed ruptured splenic artery at the pancreatic tail and near the splenic hilum. Microscopically, different stages of segmental arterial mediolysis were observed in partially thinned and aneurysmatic artery.