II. Epidemiology
- 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
- Low transverse scar (VBAC, Vaginal Birth after Cesarean): 0.8% Incidence
- Trauma in Pregnancy risk: 0.06%
III. Causes
- Rupture of uterine scar
- Cesarean Section scar (most common cause)
- Prior uterine curettage or perforation
- Abdominal Trauma
-
Trauma in Pregnancy
- High velocity collision
- More often in third trimester
- Associated with Pelvic Fractures and Bladder injury
- Typically affects uterine fundus or uterine scar
- Obstructed labor due to Cephalopelvic Disproportion
- Uterine hyperstimulation with Labor Induction
- Oxytocin Induction and augmentation
- Cervical Ripening (Misoprostol or Dinoprostone)
- Maternal Cocaine Abuse
- Other factors
- Uterine distention
- Amnioinfusion
- Gestational Trophoblastic Neoplasia
- Difficult manual removal of placenta
- Findings not related to Uterine Rupture
- Oxytocin at high infusion rates
- Five or more contractions in 10 minutes
- Tetanic contractions lasting >90 seconds
- Phelan (1998) Obstet Gynecol 92:394-7 [PubMed]
IV. Types
- Rupture of Classical Cesarean Scar (Vertical)
- Occurs in late pregnancy or early labor
- Presents as Acute Abdominal Pain and shock
- Risk of rupture in labor as high as 9%
- Rupture of Lower Uterine segment scar
- Often occult presentation
- Occurs with Trial of Labor after Cesarean (TOLAC)
- Absolute risk of rupture
- One prior Cesarean Section: 0.6% of TOLACs
- Two prior Cesarean Sections: 3.9% of TOLACs
- Absolute risk of neonatal death: 0.02% of TOLACs
- Lydon-Rochelle (2001) N Engl J Med 345:3-8 [PubMed]
- Absolute risk of rupture
- Spontaneous Uterine Rupture
- Risk of rupture in labor is less than 0.0125%
- Multiparous woman with labor obstruction
- Strong contractions result in rupture
- Presents as Acute Abdominal Pain and bleeding
V. Signs
- Classic Signs (unreliable)
- Sudden tearing uterine pain (13% of cases)
- Vaginal Bleeding (11%)
- Decreased uterine contractions
-
Fetal Distress
- Sudden deterioration in Fetal Heart Rate pattern
- Most frequent finding
- Prolonged Late Decelerations and Fetal Bradycardia
- Most reliable sign of Uterine Rupture
- Sudden deterioration in Fetal Heart Rate pattern
- Maternal distress
- Abdominal findings
- Severe Abdominal Pain/tenderness and distention
- Fetal parts may be palpable through abdominal wall
VI. Differential Diagnosis
VII. Imaging
VIII. Diagnosis
- Intrauterine pressure catheter (unreliable sign)
- Readings may show no loss of tone despite rupture
IX. Management
-
General Resuscitation measures
- See Fetal Distress
- Intravenous FluidResuscitation
- Type and cross match for Blood Products
- Stop Oxytocin
- Maternal position change
- Subcutaneous Terbutaline to stop any contractions
- Emergent delivery (usually by Cesarean Section)
- Indication: Sudden and persistent Fetal Bradycardia
- Consider Hysterectomy after infant delivered
- Best outcomes if delivery in <17 minutes of diagnosis
- Uterine Rupture noted after delivery
- Emergent Surgery
- Repair of Uterine Rupture
- Consider Hysterectomy
- Close observation indications
- Small, asymptomatic rupture
- Rupture often occurs in lower uterine segment
- Emergent Surgery
X. Complications
- Severe maternal Hemorrhage and Anemia
- Blood loss approaches 2 liters in 50% of cases
- Average Blood Transfusion requires 5 units pRBC
- Hysterectomy (Up to 23% of Uterine Rupture cases)
- Bladder rupture (0.05%)
- Maternal mortality
- Neonatal mortality
- Rupture occurred at tertiary center: 2.6%
- Rupture occurred pre-hospital: 6%
- Trauma-related Uterine Rupture is associated with 12-20% (up to 100%) fetal mortality
XI. Prevention
- Select VBAC patients very carefully
XII. References
- Krywko and Jennings (2018) Crit Dec Emerg Med 32(4): 3-11
- Evensen (2017) Am Fam Physician 95(7): 442-9 [PubMed]
- Leung (1993) Am J Obstet Gynecol 169:945-50 [PubMed]
- Toppenberg (2002) Am Fam Physician 66(5):823-8 [PubMed]