Spontaneous oblique posterior lower segment-to-cornual uterine rupture in an unscarred primigravida at term: a case report

Spontaneous rupture of an unscarred uterus during labor is an exceptionally rare and life-threatening obstetric emergency, particularly in primigravid patients. It presents significant diagnostic challenges due to its atypical manifestations and the absence of classical uterine scarring risk factors. A 34-year-old primigravida (G1P0) at 39 weeks and 2 days of gestation presented in active, spontaneous labor. Following a secondary arrest of labor descent, she developed sudden, severe abdominal pain disproportionate to uterine contractions, maternal exhaustion, and recurrent fetal heart rate decelerations. An emergent cesarean delivery was performed. Upon entering the peritoneal cavity, 50–60 cc of meconium-stained blood was observed pooling in the vesicouterine space. Inspection of the uterus revealed an extensive 7–8 cm oblique linear rupture originating from the right posterior lower uterine segment and extending up to the left cornual region. The defect was successfully repaired in double layers, preserving maternal fertility. A healthy male infant was delivered with excellent Apgar scores (9 at 1 min, 10 at 5 min), and both mother and neonate experienced an uneventful postoperative recovery. This case underscores the high index of clinical suspicion required to identify uterine rupture in nulliparous women with no history of uterine surgery. The presence of meconium-stained hemoperitoneum prior to hysterotomy may represent a potential intraoperative clue of an atypical rupture, necessitating thorough uterine exploration to ensure timely, life-saving repair and fertility preservation.