8.3 Uterine Rupture & Acute Uterine Inversion
Key Takeaways
- Uterine rupture is a catastrophic obstetric disruption defined as the complete anatomical separation of all myometrial layers and overlying visceral peritoneum, resulting in extrusion of the fetus, placenta, and amniotic fluid into the maternal peritoneal cavity and life-threatening maternal-fetal hemorrhage.
- The single most significant predisposing risk factor for uterine rupture is a prior scarred uterus (e.g., prior cesarean delivery or transmural myomectomy); classical (vertical) uterine incisions carry a 4% to 9% rupture risk, compared to a 0.5% to 0.9% risk with a prior low transverse incision during Trial of Labor After Cesarean (TOLAC).
- The most consistent, sensitive, and earliest clinical indicator of uterine rupture is a sudden, severe, non-reassuring fetal heart rate abnormality (Category III tracing, prolonged severe deceleration, or terminal bradycardia), occurring in >70% of cases; classic signs such as sudden tearing abdominal pain, cessation of uterine contractions, loss of fetal station, and maternal hypovolemic shock occur unpredictably.
- Acute uterine inversion is the turning inside out of the uterine fundus into the endometrial cavity, through the cervix, or beyond the vaginal introitus; primary etiologies include aggressive premature umbilical cord traction prior to placental separation, excessive fundal pressure applied to an atonic, relaxed uterus, and morbidly adherent placenta (placenta accreta spectrum).
- The emergent management of acute uterine inversion requires immediate cessation of all uterotonic infusions, immediate administration of uterine-relaxing tocolytics (IV nitroglycerin, terbutaline, or general volatile anesthesia), manual uterine repositioning using the Johnson maneuver (pushing the fundus upward along the pelvic axis toward the umbilicus), leaving the attached placenta intact until the uterus is fully repositioned, and subsequently administering high-dose uterotonics and bimanual compression to maintain uterine contraction.
Last updated: August 2026
Anatomy, Definitions & Pathophysiology
1. Uterine Rupture vs. Uterine Scar Dehiscence
- Complete Uterine Rupture: A catastrophic full-thickness disruption of the myometrium, including the overlying visceral serosa (peritoneum). The uterine cavity communicates directly with the maternal peritoneal cavity. The fetus, placenta, umbilical cord, and massive quantities of blood escape into the abdominal cavity, producing rapid fetal asphyxia from complete loss of uteroplacental perfusion, accompanied by torrential maternal intra-abdominal hemorrhage and severe hypovolemic shock.
- Incomplete Uterine Dehiscence (Uterine Window): A partial-thickness separation of a pre-existing myometrial surgical scar where the overlying visceral peritoneum remains intact. The amniotic sac and fetus remain contained within the uterine cavity. Dehiscence is frequently asymptomatic, causes minimal or no bleeding, does not impair fetal oxygenation, and is typically discovered incidentally during repeat cesarean delivery.
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| COMPARISON: COMPLETE UTERINE RUPTURE VS. SCAR DEHISCENCE |
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Feature Complete Uterine Rupture Incomplete Uterine Scar Dehiscence
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Anatomical Extent Full-thickness (Endometrium, Partial separation (Myometrium only;
Myometrium, Visceral Peritoneum) Visceral Serosa remains INTACT)
Peritoneal Spillage Fetus, placenta, blood in abdomen None (Amniotic sac & fetus in uterus)
FHR Tracing Category III Bradycardia / Severe Decels Typically Normal / Category I
Maternal Hemodynamics Massive Hemorrhage / Shock / Collapse Hemodynamically Stable / Asymptomatic
Clinical Urgency Emergency Laparotomy / Stat Cesarean Managed electively or observed
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2. Acute Uterine Inversion
Acute uterine inversion occurs when the fundus of the uterus collapses inward and turns inside out, prolapsing into the lower uterine cavity, through the cervical ring, or completely outside the vaginal introitus. It is a dual emergency characterized by sudden catastrophic hemorrhage and profound neurogenic shock:
- Neurogenic Shock Mechanism: As the heavy uterine fundus inverts and pulls downward, it exerts intense traction on the broad ligaments, infundibulopelvic ligaments, ovaries, and visceral peritoneal pain fibers. This massive visceral stretch triggers powerful parasympathetic vagal nerve stimulation, causing acute profound bradycardia, hypotension, and cardiovascular collapse out of proportion to visible external blood loss.
- Hemorrhagic Shock Mechanism: Inversion mechanically disrupts the interlacing 'physiologic ligature' smooth muscle fibers of the myometrium, preventing them from constricting the spiral arteries at the placental implantation site, resulting in massive, unhindered uterine atony and hemorrhage.
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| STAGES OF ACUTE UTERINE INVERSION |
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Stage 1 (Incomplete): Fundus inverts into the uterine cavity but does not pass through cervix
Stage 2 (Complete): Fundus passes completely through the cervical os into the vaginal vault
Stage 3 (Prolapsed): Inverted fundus protrudes completely outside the vaginal introitus
Stage 4 (Total): Both the uterus and vaginal canal are completely inverted and externalized
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Uterine Rupture: Risk Factors & Clinical Manifestations
Risk Stratification for Uterine Rupture
| Clinical Category | Specific Risk Factor | Estimated Rupture Risk & Clinical Considerations |
|---|---|---|
| Prior Uterine Surgery | • Prior Classical (Vertical) Cesarean Incision<br/>• Prior T-incision or J-incision<br/>• Prior Transmural Myomectomy entering endometrial cavity<br/>• Prior Low Transverse Cesarean (TOLAC) | • 4% to 9% (TOLAC strictly contraindicated; planned cesarean at 36 0/7–37 0/7 wk)<br/>• 4% to 9% (TOLAC contraindicated)<br/>• Large transmural scars carry elevated risk<br/>• 0.5% to 0.9% (ACOG supports TOLAC in appropriate candidates) |
| Uterotonic Agents | • Misoprostol (PGE1) or Dinoprostone (PGE2) in scarred uterus<br/>• High-dose Oxytocin hyperstimulation | • Misoprostol is strictly contraindicated for labor induction in patients with a prior cesarean or major uterine scar.<br/>• Excessive tachysystole increases mechanical wall tension. |
| Obstetric Factors | • Grand multiparity (≥5 deliveries)<br/>• Obstructed labor / Cephalopelvic Disproportion (Bandl's ring)<br/>• Uterine overdistension (polyhydramnios, high-order multiples) | Thinning of lower uterine segment under severe mechanical strain. |
Clinical Manifestations & Diagnostic Signs of Uterine Rupture
Contrary to classical textbook descriptions, uterine rupture rarely presents with sudden sharp tearing pain followed by complete relief. Because many laboring patients have effective neuraxial (epidural) analgesia, pain is often masked or absent. The inpatient obstetric nurse must recognize the spectrum of clinical indicators:
- Fetal Heart Rate Abnormality (Most Sensitive & Earliest Sign): Occurs in >70% to 80% of ruptures. Manifests as sudden, severe prolonged decelerations, recurrent late decelerations with loss of variability, or persistent terminal bradycardia (<80 bpm).
- Loss of Fetal Station (Floating Presenting Part): A fetal vertex or breech that was previously well-engaged at +1 or +2 station suddenly recedes and floats freely above the pelvic inlet (-3 station) on digital vaginal examination as the fetus is extruded through the myometrial tear into the peritoneal cavity.
- Cessation of Uterine Contractions / Loss of IUPC Baseline: If an IUPC is present, the tracing may show a sudden loss of contraction amplitude and a sharp decline in baseline uterine resting tone, though IUPC tracings can remain deceptively normal if abdominal muscle tone is high.
- Abnormal Palpation of Fetal Parts: Fetal small parts (limbs, torso) become easily palpable directly beneath the maternal abdominal wall, alongside a firm, contracted, displaced empty uterine mass.
- Maternal Hypovolemic Shock & Pain: Rapid maternal tachycardia, profound hypotension, pallor, diaphoresis, shortness of breath from hemoperitoneum diaphragmatic irritation (Kehr's sign / shoulder tip pain), and variable vaginal or intra-abdominal bleeding.
Emergency Management of Uterine Rupture
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| EMERGENCY MANAGEMENT PROTOCOL: UTERINE RUPTURE |
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[ Acute Suspicion / Confirmation of Rupture ]
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[ ACTIVATE CODE OB / MTP ] [ IMMEDIATE INTRAUTERINE RESUSCITATION ]
• Stat page Obstetrician, Anesthesia, • Discontinue all Oxytocin / uterotonics
Neonatology, Operating Room Team • Administer 100% O2 via NRB mask at 10 L/min
• Activate Massive Transfusion Protocol (MTP) • Rapid IV crystalloid infusion (2 large-bore lines)
• Prepare blood bank for uncrossmatched O-neg • Place patient in left lateral position
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└────────────────────────────────┬────────────────────────────────┘
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[ IMMEDIATE EMERGENCY STAT LAPAROTOMY / CESAREAN ]
• Transport to OR immediately under general anesthesia.
• Deliver infant and placenta; hand off to Neonatology.
• Achieve rapid surgical hemostasis.
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┌────────────────────────────────┴────────────────────────────────┐
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[ SURGICAL REPAIR OF DEFECT ] [ EMERGENCY CESAREAN HYSTERECTOMY ]
• Indicated if laceration is clean, linear, • Indicated if rupture is extensive, jagged,
hemostasis is achievable, and patient involves uterine vessels/cervix, or maternal
desires future fertility. coagulopathy/intractable bleeding occurs.
Emergency Management of Acute Uterine Inversion
Acute uterine inversion is one of the few obstetric emergencies where pharmacological and mechanical steps must be performed in a rigid, counter-intuitive sequence to prevent fatal maternal hemorrhage and complete shock.
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| STEPWISE RESUSCITATION PROTOCOL: ACUTE UTERINE INVERSION |
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[ STEP 1 ] - ACTIVATE EMERGENCY TEAM & STOP ALL UTEROTONICS IMMEDIATELY
• Call Code OB / Stat Anesthesia / Stat Obstetrician.
• STOP Pitocin / Oxytocin immediately! (Uterotonics constrict the lower cervical ring,
trapping the inverted fundus outside and making manual replacement impossible).
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[ STEP 2 ] - ESTABLISH AGGRESSIVE HEMODYNAMIC & NEUROGENIC RESUSCITATION
• Insert two large-bore (14- or 16-gauge) IV lines.
• Rapid crystalloid bolus; prepare Blood Bank / Transfusion for massive hemorrhage.
• If severe vagal bradycardia / neurogenic shock: Administer IV ATROPINE 0.5-1.0 mg.
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[ STEP 3 ] - ADMINISTER UTERINE-RELAXING TOCOLYTIC AGENTS
• The tight, contracted lower uterine segment / cervical ring must be relaxed.
• Administer fast-acting tocolytics:
- IV NITROGLYCERIN: 50 to 200 mcg IV bolus (rapid onset, short duration)
- Subcutaneous TERBUTALINE: 0.25 mg SQ
- General Anesthesia with halogenated volatile gas (sevoflurane/isoflurane)
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[ STEP 4 ] - PERFORM IMMEDIATE MANUAL REPLACEMENT (THE JOHNSON MANEUVER)
• DO NOT REMOVE THE ATTACHED PLACENTA! (Removing placenta before replacement causes
immediate catastrophic torrential hemorrhage from open uncontracted sinuses).
• Clinician grasps inverted fundus in the palm of hand, with fingertips supporting the
cervical-uterine junction.
• Push the fundus firmly UPWARD along the anatomical axis of the pelvis toward the
maternal umbilicus, lifting the entire uterus above the pelvic brim until it snaps
back into normal anatomical configuration.
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[ STEP 5 ] - RE-ESTABLISH UTERINE TONE & REMOVE PLACENTA
• ONLY AFTER the fundus is completely restored to its anatomical position:
a) Discontinue tocolytics / volatile anesthetics.
b) Administer high-dose UTEROTONICS (Oxytocin infusion 40-80 units, Methergine,
Carboprost, Misoprostol, Tranexamic Acid [TXA] 1 g IV).
c) Manually separate and extract the placenta if still adherent.
d) Maintain bimanual uterine compression (one hand inside cavity supporting fundus,
one hand compressing externally on abdomen) until myometrium is firmly contracted.
e) Consider Bakri intrauterine balloon placement to prevent re-inversion.
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[ STEP 6 ] - SURGICAL MANAGEMENT IF MANUAL REPLACEMENT FAILS
• If Johnson maneuver fails due to rigid constriction ring (Bandl's contraction ring):
- Huntington Procedure: Laparotomy; grasp round ligaments with Allis clamps and
apply upward traction while an assistant pushes upward from vagina.
- Haultain Procedure: Vertical incisional division of the posterior cervical
constriction ring to release the trapped fundus, followed by surgical closure.
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Test Your Knowledge
A G2P1 at 40 weeks of gestation with a prior low transverse cesarean section is undergoing a Trial of Labor After Cesarean (TOLAC). During active labor at 7 cm dilatation, the fetal heart rate suddenly drops from 140 bpm to 65 bpm and remains at that level for 2 minutes. On sterile vaginal examination, the nurse notes that the fetal vertex, which was previously engaged at +1 station, is no longer palpable in the pelvis and has receded into the upper abdomen. What is the priority diagnosis and immediate action?
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D
Test Your Knowledge
Immediately following the vaginal birth of a term infant, the obstetric provider applies vigorous cord traction while the uterus is relaxed and uncontracted. The patient suddenly cries out in pain, becomes pale and diaphoretic, and displays a blood pressure of 65/38 mmHg with a heart rate of 48 bpm. On perineal inspection, a large, beefy-red globular mass is visualized protruding from the vaginal introitus with the placenta still firmly attached. What is the nurse's first immediate pharmacologic action?
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D
Test Your Knowledge
During the emergency management of an acute, complete uterine inversion where the placenta remains adherent to the inverted fundus, what is the correct evidence-based management regarding the attached placenta?
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B
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D
Test Your Knowledge
Which of the following patients carries the highest relative risk for sustaining a complete uterine rupture during labor?
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B
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D