Uterine Rupture

What uterine rupture is

The uterus is a thick muscular organ. During labor it contracts powerfully and stretches. If part of the wall is weakened, usually by a scar, it can tear open.

• Complete rupture: the tear goes through all layers, including the outer lining (serosa). The baby, placenta or umbilical cord may move partly or fully into the abdomen, and bleeding can be massive.
• Uterine dehiscence (incomplete rupture): the scar separates but the outer layer stays intact. It is often silent and found at a repeat cesarean, and usually causes much less harm.

Risk factors

Previous surgery on the uterus

The biggest risk factor is a previous cesarean delivery. The risk depends on the type of incision on the uterus (which can differ from the skin scar):

Other uterine surgery, such as removing fibroids (myomectomy) when the cavity was entered, or repair of a previous rupture, also raises the risk.

Factors in labor

• Induction or augmentation of labor, especially with prostaglandins. Misoprostol is not used for people with a prior cesarean in the third trimester because of the higher rupture risk. Oxytocin is used with caution.
• Prolonged or obstructed labor, for example from a very large baby or a narrow pelvis
• Short interval between pregnancies, generally under 18 months from a cesarean to the next birth

Other factors

• abdominal trauma such as a car crash
• having had many previous births
• abnormal placental attachment (placenta accreta) into a scar
• congenital uterine abnormalities
• forceful instrument deliveries or internal maneuvers

Signs and symptoms

The signs can develop quickly, and no single sign is always present.

• Changes in the baby's heart rate: a sudden, prolonged slowing (bradycardia) or abnormal patterns on monitoring. This is the most common and often the first sign.
• Abdominal pain: sudden, sharp or tearing pain, or new pain over the scar that persists between contractions. An epidural may mask it.
• Vaginal bleeding, though bleeding may be mostly internal and hidden
• Contractions slowing or stopping
• The baby's head moving back up the birth canal (loss of station)
• Change in the shape of the belly, or parts of the baby felt easily under the skin
• Signs of shock in the mother: fast heart rate, low blood pressure, dizziness, pale and clammy skin
• Shoulder tip pain or chest pain from blood irritating the diaphragm

Diagnosis

Uterine rupture is usually suspected from a combination of fetal heart rate changes, maternal symptoms and labor progress. Because delay is dangerous, doctors move straight to surgery rather than waiting for imaging. Ultrasound may help in some stable situations, for example after trauma or before labor, but the diagnosis is confirmed at operation. Placental abruption can cause similar pain, bleeding and fetal distress and is managed with the same urgency.

Treatment

Uterine rupture is a surgical emergency:

1. Resuscitation: large IV lines, fluids, blood and blood products, oxygen.
2. Emergency laparotomy and delivery: the baby is delivered by cesarean as fast as possible, ideally within minutes of diagnosis, because outcomes for the baby worsen with each minute of delay.
3. Repair or hysterectomy: if the tear is clean and bleeding can be controlled, the surgeon repairs it. If the damage is extensive, bleeding cannot be stopped, or the tear extends into major vessels, a hysterectomy (removal of the uterus) is needed.
4. Treatment of complications: including hemorrhagic shock, bladder injury and infection.

Complications

For the mother

• severe blood loss requiring transfusion, often continuing as postpartum hemorrhage
• hysterectomy and loss of future fertility
• bladder or ureter injury
• infection
• rarely, death, particularly where emergency surgery and blood are not available quickly

For the baby

• lack of oxygen, which can cause brain injury
• admission to neonatal intensive care
• stillbirth or newborn death in a minority of cases

Future pregnancies

People who have had a uterine rupture repaired have a high risk of rupture in a later pregnancy. They are usually advised to:

• have a planned cesarean before labor starts, typically around 36 to 37 weeks
• be monitored closely in a hospital with obstetric surgical services
• consider waiting at least 18 months before a new pregnancy

VBAC: weighing the risk

For most people with one previous low transverse cesarean, a trial of labor after cesarean (TOLAC) is a reasonable option recommended by ACOG. About 60 to 80% achieve a vaginal birth, which avoids the risks of repeat surgery. The small risk of rupture means labor should take place in a hospital able to perform an emergency cesarean immediately, with continuous fetal heart monitoring. Discuss with your obstetrician:

• the type of incision used before (check your operation notes)
• how many cesareans you have had and the interval since the last one
• the reasons for your previous cesarean
• whether induction may be needed

Frequently asked questions

What are the first signs of uterine rupture?

The earliest sign is often a sudden drop or abnormal pattern in the baby's heart rate on monitoring. The mother may feel sudden, severe or tearing belly pain, especially over a previous scar, notice bleeding or feel faint. Contractions may stop. Any of these during labor needs immediate assessment.

What is the risk of uterine rupture after a C-section?

After one low transverse cesarean, the risk during labor is about 0.5 to 0.9%, or roughly 1 in 110 to 1 in 200. The risk is higher with a classical (vertical) uterine incision, multiple cesareans, a short gap between pregnancies, or induction of labor, particularly with prostaglandins.

Can a uterus rupture before labor?

Yes, but this is much less common. Rupture before labor is most associated with a previous classical cesarean, prior uterine rupture, extensive fibroid surgery, abnormal placental attachment into a scar, or major trauma such as a car crash. Sudden severe belly pain in pregnancy always needs emergency care.

Can you get pregnant after a uterine rupture?

If the uterus was repaired rather than removed, pregnancy is possible. The risk of another rupture is high, so a planned cesarean before labor, usually around 36 to 37 weeks, is recommended, with care in a specialist hospital. Allow time to heal, ideally at least 18 months, before conceiving.

How fast does a baby need to be delivered after uterine rupture?

As quickly as possible. Studies show the baby's risk of oxygen deprivation rises sharply when delivery is delayed beyond about 10 to 20 minutes after signs appear. That is why VBAC is advised only in hospitals that can perform an immediate emergency cesarean.