First-trimester uterine rupture in a scarred uterus: a case report.

First-trimester uterine rupture is a rare but potentially fatal complication of pregnancy. It usually presents a diagnostic challenge because intrauterine gestation may still be visible on ultrasound even after uterine rupture with associated hemoperitoneum. The typical signs of uterine rupture, including abdominal tenderness, hemoperitoneum, and hemodynamic instability, become the guiding principle when considering a decision on emergency laparotomy. In patients with previous uterine scars, first-trimester ultrasonography should focus on excluding early placenta accreta spectrum, a condition that may lead to uterine rupture during the first trimester. A high index of suspicion is required in diagnosing a first-trimester uterine rupture.