Background <p>Spontaneous rupture of the spleen during pregnancy or after delivery is an extremely rare, potentially life-threatening complication that poses major diagnostic and therapeutic challenges.</p> Case presentation <p>A 33-year-old woman at 27 weeks of gestation presented with a 1-week history of polyhydramnios and progressive abdominal distension. She had no history of trauma and recognized risk factors. On presentation, abdominal ultrasonography demonstrated large-volume ascites, which was not evident on the initial non-contrast whole-abdominal CT performed because of maternal instability. The patient showed a progressive decline in hemoglobin and abnormal fetal umbilical artery flow. After multidisciplinary consultation involving surgery, obstetrics/gynecology, radiology/ultrasound, and neonatology, an emergency cesarean delivery with exploratory laparotomy was undertaken. Intraoperative exploration revealed active hemorrhage originating near the splenic hilum with a ruptured splenic capsule and omental adhesions. A total splenectomy was performed after family consent after discussion with the team, and postoperative paraffin-embedded tissue confirmed spontaneous splenic rupture. However, this was a rare case. We hypothesize that marked polyhydramnios with increased intra-abdominal pressure and traction of omental adhesions contributed to splenic capsular rupture, intraperitoneal hemorrhage, and hemorrhagic shock.</p> Conclusion <p>This case emphasizes the importance of close monitoring of amniotic fluid volume and prompt evaluation of acute abdominal pain in pregnancy, particularly in patients with polyhydramnios. Our review of published literature highlights that spontaneous splenic rupture, although rare, can occur during the antenatal period and is frequently associated with delayed diagnosis and poor outcomes. Early recognition and timely surgical intervention remain essential for improving maternal and fetal survival.</p>