Uterine rupture

Learning objectives

Uterine rupture refers to a complete division of all three layers of the uterus: the endometrium (inner epithelial layer), myometrium (smooth muscle layer), and perimetrium (serosal outer surface)
Typical rupture occurs during labor, but it may occasionally happen earlier in pregnancy
The fetus is left without the protection of the uterus, leaving the fetus without oxygen and causing the fetus’s heart rate to slow down
Suspect uterine rupture based on a rapid drop in the baby’s heart rate during labor
The cardinal sign of uterine rupture is loss of fetal station on a manual vaginal exam
The maternal mortality rate is < 1%, fetal mortality rate is between 2-6 %
Incomplete rupture:
- Peritoneum is still intact
Complete rupture:
- All three layers are ruptured
- The contents of the uterus spill into the peritoneal cavity or the broad ligament
Bladder injury is not uncommon with uterine rupture
A caesarean section is recommended in women who have had a prior rupture

Vaginal bleeding
Abdominal pain and tenderness
Chest pain, pain between the scapulae, or pain on inspiration
Hypovolemic shock
Signs associated with fetal oxygenation:
- Late deceleration
- Reduced variability
- Tachycardia
- Bradycardia
Absent fetal heart sounds
Cessation of uterine contractions
Palpation of the fetus outside the uterus (usually occurs only with a large, complete rupture)

Maternal	Fetal
Major maternal blood loss A higher risk of Coagulopathy Longer fetal exposure to hypoxia Hysterectomy	Intraventricular hemorrhage Seizures Brain ischemia Death

Laboratory tests:
- Hemoglobin or hematocrit
- Coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen, thromboelastogram)
Ultrasound
- To rule out placenta praevia, placental abruption, or spontaneous abortion
- To support the diagnosis: abnormality in the uterine wall, a hematoma next to hysterotomy scar, free fluid in the peritoneum, anhydramnios or fetal parts outside the uterus