Uterine Rupture

Overall risk: Up to 0.03 to 0.08% of all deliveries
Uterine scar risk: Up to 0.3 to 1.7% of all deliveries with prior cesarean
1. Low transverse scar (VBAC, Vaginal Birth after Cesarean): 0.8% Incidence
Trauma in Pregnancy risk: 0.06%

Rupture of uterine scar
1. Cesarean Section scar (most common cause)
2. Prior uterine curettage or perforation
3. Abdominal Trauma
Trauma in Pregnancy
1. High velocity collision
2. More often in third trimester
3. Associated with Pelvic Fractures and Bladder injury
4. Typically affects uterine fundus or uterine scar
Obstructed labor due to Cephalopelvic Disproportion
Uterine hyperstimulation with Labor Induction
1. Oxytocin Induction and augmentation
2. Cervical Ripening (Misoprostol or Dinoprostone)
3. Maternal Cocaine Abuse
Other factors
1. Uterine distention
2. Amnioinfusion
3. Gestational Trophoblastic Neoplasia
4. Difficult manual removal of placenta
Findings not related to Uterine Rupture
1. Oxytocin at high infusion rates
2. Five or more contractions in 10 minutes
3. Tetanic contractions lasting >90 seconds
4. Phelan (1998) Obstet Gynecol 92:394-7 [PubMed]

Rupture of Classical Cesarean Scar (Vertical)
1. Occurs in late pregnancy or early labor
2. Presents as Acute Abdominal Pain and shock
3. Risk of rupture in labor as high as 9%
Rupture of Lower Uterine segment scar
1. Often occult presentation
2. Occurs with Trial of Labor after Cesarean (TOLAC)
  1. Absolute risk of rupture
    1. One prior Cesarean Section: 0.6% of TOLACs
    2. Two prior Cesarean Sections: 3.9% of TOLACs
  2. Absolute risk of neonatal death: 0.02% of TOLACs
  3. Lydon-Rochelle (2001) N Engl J Med 345:3-8 [PubMed]
Spontaneous Uterine Rupture
1. Risk of rupture in labor is less than 0.0125%
2. Multiparous woman with labor obstruction
  1. Fetal Malpresentation
  2. Cephalopelvic Disproportion
3. Strong contractions result in rupture
4. Presents as Acute Abdominal Pain and bleeding

Classic Signs (unreliable)
1. Sudden tearing uterine pain (13% of cases)
2. Vaginal Bleeding (11%)
3. Decreased uterine contractions
Fetal Distress
1. Sudden deterioration in Fetal Heart Rate pattern
  1. Most frequent finding
2. Prolonged Late Decelerations and Fetal Bradycardia
3. Most reliable sign of Uterine Rupture
Maternal distress
1. Hypotension
2. Tachycardia
Abdominal findings
1. Severe Abdominal Pain/tenderness and distention
2. Fetal parts may be palpable through abdominal wall

Intrauterine pressure catheter (unreliable sign)
1. Readings may show no loss of tone despite rupture

General Resuscitation measures
1. See Fetal Distress
2. Intravenous Fluid Resuscitation
3. Type and cross match for Blood Products
4. Stop Oxytocin
5. Maternal position change
6. Subcutaneous Terbutaline to stop any contractions
Emergent delivery (usually by Cesarean Section)
1. Indication: Sudden and persistent Fetal Bradycardia
2. Consider Hysterectomy after infant delivered
3. Best outcomes if delivery in <17 minutes of diagnosis
Uterine Rupture noted after delivery
1. Emergent Surgery
  1. Repair of Uterine Rupture
  2. Consider Hysterectomy
2. Close observation indications
  1. Small, asymptomatic rupture
  2. Rupture often occurs in lower uterine segment

Severe maternal Hemorrhage and Anemia
1. Blood loss approaches 2 liters in 50% of cases
2. Average Blood Transfusion requires 5 units pRBC
Hysterectomy (Up to 23% of Uterine Rupture cases)
Bladder rupture (0.05%)
Maternal mortality
1. Rare, except pre-hospital rupture and Trauma
2. Trauma-related Uterine Rupture is associated with 10% (up to 20-65%) maternal mortality
Neonatal mortality
1. Rupture occurred at tertiary center: 2.6%
2. Rupture occurred pre-hospital: 6%
3. Trauma-related Uterine Rupture is associated with 12-20% (up to 100%) fetal mortality