What are the ultrasound findings of uterine rupture?

From the Guidelines

Uterine rupture is a life-threatening obstetric emergency that requires immediate surgical intervention, and ultrasound is the primary imaging modality for diagnosis, with findings including discontinuity or defects in the uterine wall, hemoperitoneum, and abnormal fetal position. When evaluating a patient with suspected uterine rupture, a comprehensive ultrasound examination should be performed immediately, focusing on the integrity of all uterine walls, particularly at sites of previous cesarean scars or myomectomies 1. Key ultrasound findings of uterine rupture include:

• Discontinuity or defects in the uterine wall
• Hemoperitoneum (free fluid in the abdominal cavity)
• Abnormal fetal position outside the uterine cavity
• Empty uterus with fetus located elsewhere Color Doppler may help identify increased vascularity or bleeding at the rupture site 1. Complete uterine rupture occurs most commonly in women with previous uterine surgery, particularly cesarean sections, during labor or late pregnancy, and the classic clinical presentation includes sudden severe abdominal pain, vaginal bleeding, fetal distress, and maternal shock, though ultrasound confirmation is crucial as symptoms may be variable or nonspecific 1. In cases where ultrasound findings are unclear, MRI may be used to distinguish and/or confirm uterine dehiscence versus rupture, particularly when it is confusing on ultrasound (US) or CT 2. However, given the urgency of the situation, immediate surgical intervention is often necessary, and ultrasound remains the primary diagnostic tool due to its availability and speed. Early detection through ultrasound can significantly improve maternal and fetal outcomes in this emergency situation, and a high index of suspicion for uterine rupture is essential in patients with risk factors, particularly those with previous uterine surgery. In the setting of hemorrhage, CT with intravenous (IV) contrast may also be used to determine whether active ongoing hemorrhage is present, to localize the bleeding, and to identify the source, although its role is secondary to ultrasound in the diagnosis of uterine rupture 1.

From the Research

Uterine Rupture Diagnosis and Management

• Uterine rupture is a life-threatening obstetrical emergency that can be diagnosed by ultrasound, as demonstrated in a case study published in 2008 3.
• The use of ultrasound in diagnosing uterine rupture is crucial, as it can demonstrate uterine laceration and intra-abdominal dislocation of placenta and fetus 3.
• Uterine rupture is an uncommon obstetric event, but it is associated with maternal mortality, particularly in developing countries, and with major maternal morbidity, including peripartum hysterectomy 4.

Risk Factors and Clinical Presentation

• The key factor in the cause of rupture is whether or not the uterus is scarred, with rupture of an unscarred uterus being rare and usually traumatic 4.
• Rupture of the scarred uterus is more common and usually occurs after a trial of labor in a patient with a previous Caesarean section 4.
• There are no reliable predictors or unequivocal clinical manifestations of rupture, so physicians must maintain a high index of suspicion for possible rupture, especially in the presence of fetal bradycardia or other evidence of fetal distress 5.

Management and Treatment

• Management of uterine rupture involves surgery for prompt delivery of the infant and control of maternal hemorrhage, with newborns often requiring admission to an intensive care nursery 5.
• Laparoscopic management of suspected postpartum uterine rupture is feasible and safe in hemodynamically stable women, with a novel approach being explored in a study published in 2022 6.
• In cases of unscarred uterine rupture with catastrophic hemorrhage, immediate exploratory laparotomy followed by life-saving hysterectomy may be necessary, as described in a study published in 2023 7.