Massive Hemoperitoneum Caused by Spontaneous Rupture of a Superficial Uterine Fundal Vein During Preterm Labor: A Case Report.

Spontaneous hemoperitoneum in pregnancy is rare, and rupture of a superficial uterine fundal vein in an unscarred uterus is exceptionally uncommon. A 37-year-old woman at 27 + 0 weeks presented with left upper quadrant abdominal pain, and imaging revealed a localized hematoma adjacent to the left uterine fundus without active bleeding. During conservative management, she developed sudden severe pain with fetal heart rate decelerations at 27 + 6 weeks, prompting emergency cesarean delivery. Intraoperative findings showed approximately 2400 mL of hemoperitoneum caused by rupture of a superficial fundal vein, with the uterus otherwise intact, and bleeding was controlled with a fibrin sealant patch. Maternal recovery and neonatal outcome were favorable. This case underscores that rupture of superficial uterine veins should be considered in pregnant patients presenting with unexplained hemoperitoneum during pregnancy.