Background: Rupture of a pregnant uterus occurs most often in a scarred uterus, and spontaneous rupture of a non-scarred uterus in the early second trimester is rare.
Case: A woman with two previous normal vaginal deliveries and no prior trauma to the uterus presented at 16 weeks' gestation with an acute abdomen due to intraperitoneal hemorrhage. A large rupture of the fundus of the uterus was found. A supracervical hysterectomy was carried out, with subsequent good recovery. The specimen showed placenta percreta.
Conclusion: Spontaneous rupture of an unscarred uterus, due to placenta percreta, should be considered in cases of acute intraperitoneal hemorrhage, even in early pregnancy.