A13. Uterine rupture

Rupture of the uterus is a life-threatening complication for both the mother and the foetus. It mostly occurs during labour, and mostly in people who’ve had a previous C-section (vaginal birth after C-section, VBAC). However, it can also occur antepartum and in women without previous surgery. It’s an obstetric emergency which requires emergency surgery.

In a uterine rupture the uterus opens into the abdominal cavity. In case of uterine dehiscence, a related condition, there is a defect in the uterine wall, but the defect is covered by visceral peritoneum. This is usually asymptomatic and discovered incidentally.

Etiology

Previous uterine surgery, mostly from C-section but also from myomectomy, is the most important risk factor for uterine rupture. The resulting uterine scar is a defect in the uterus which may rupture as the uterus distends. However, uterine rupture may also occur without uterine scar, although this is rare.

Factors which predispose to excessive uterine distension also increase the risk for rupture:

• Foetal macrosomia
• Foetal malpresentation
• Inappropriate use of uterotonics (oxytocin)

Clinical features

Possible signs of pending uterine rupture include:

• Presence of Bandl’s ring above the umbilicus
• Excessive uterine activity (frequent, strong contractions)
• Overdistended and tender lower uterine segment
• Vaginal bleeding
• Macrohaematuria

Symptoms of manifest uterine rupture include pathological CTG (especially foetal bradycardia), vaginal bleeding, and severe abdominal pain. There may be major intraabdominal haemorrhage despite modest vaginal bleeding; haemodynamic instability may occur and may be the cause of presentation. If occurring during labour, there will be a sudden cessation of contractions.

Foetal parts may be palpable through the maternal abdomen, as the foetus may leave the uterine cavity through the uterine rupture. Loss of foetal station, referring to the presenting part moving back up into the uterine cavity, is typical.

Diagnosis and evaluation

The diagnosis is clinical and based on typical clinical features. In suspected cases the patient should be taken immediately to surgery for laparotomy.

Treatment

Uterine rupture must be managed by emergency C-section, followed by hysterectomy or uterine repair.

Complications

• Major intraabdominal haemorrhage
• Bladder rupture
• Foetal or maternal death