II. Epidemiology

  1. Overall risk: Up to 0.03 to 0.08% of all deliveries
  2. Uterine scar risk: Up to 0.3 to 1.7% of all deliveries

III. Etiology

  1. Rupture of uterine scar
    1. Cesarean Section scar (most common cause)
    2. Prior uterine curettage or perforation
    3. Abdominal Trauma
  2. Obstructed labor due to Cephalopelvic Disproportion
  3. Uterine hyperstimulation with Labor Induction
    1. Cervical Ripening (Misoprostol or Dinoprostone)
    2. Maternal Cocaine Abuse
  4. Other factors
    1. Uterine distention
    2. Amnioinfusion
    3. Gestational Trophoblastic Neoplasia
    4. Difficult manual removal of placenta
  5. 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]

IV. Types

  1. 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%
  2. 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]
  3. 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

V. Signs

  1. Classic Signs (unreliable)
    1. Sudden tearing uterine pain (13% of cases)
    2. Vaginal Bleeding (11%)
    3. Decreased uterine contractions
  2. Fetal Distress
    1. Sudden deterioration in Fetal Heart Rate pattern
      1. Most frequent finding
    2. Prolonged Late Decelerations and Bradycardia
    3. Most reliable sign of Uterine Rupture
  3. Maternal distress
    1. Hypotension
    2. Tachycardia

VI. Differential Diagnosis

VII. Diagnosis

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

VIII. Management

  1. General Resuscitation measures
    1. See Fetal Distress
    2. Intravenous FluidResuscitation
    3. Type and cross match for Blood Products
    4. Stop Oxytocin
    5. Maternal position change
    6. Subcutaneous Terbutaline to stop any contractions
  2. 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
  3. 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

IX. Complications

  1. Severe maternal Hemorrhage and Anemia
    1. Blood loss approaches 2 liters in 50% of cases
    2. Average Blood Transfusion requires 5 units pRBC
  2. Hysterectomy (Up to 23% of Uterine Rupture cases)
  3. Bladder rupture (0.05%)
  4. Maternal mortality (rare, except pre-hospital rupture)
  5. Neonatal mortality
    1. Rupture occurred at tertiary center: 2.6%
    2. Rupture occurred pre-hospital: 6%

X. Prevention

  1. Select VBAC patients very carefully

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