What Is Uterine Rupture?

Uterine rupture is a rare but life-threatening complication that can happen during childbirth. Knowing the causes, warning signs, and preventive measures for safe maternity care is important. Uterine rupture means the uterus tears through all its layers, which are the inner lining, the muscle layer, and the outer surface.¹

When the uterus ruptures, all its layers are torn apart. This can be extremely dangerous to both the mother and the baby, so doctors need to be on the lookout for any symptoms. Most of the time, it occurs during pregnancy, but it can also, very rarely, happen to women who are not pregnant due to trauma, infections, or cancer.² The most common cause is when people have had a previous C-section and then attempt a vaginal delivery.

In the UK, it is uncommon in 2 out of every 10,000 pregnancies and 0.2% of women who have had past C-sections. A severe uterine scar rupture occurs when the outer layer of the uterine wall completely tears. Foetal discomfort seen on monitoring by a change in the heart rate, significant bleeding, or the baby or placenta shifting into the abdomen can result from this.²

Uterine rupture leads to abdominal pain, vaginal bleeding, changes in contractions, and problems with the baby's heart rate.¹

Uterine anatomy

A woman's lower belly contains the uterus, a pear-shaped organ. It is crucial for pregnancy, menstruation, and childbirth. It can occasionally develop improperly before birth, resulting in various variations, including having a wall inside of it or two separate uteri.

The uterus is in the lower belly, in front of the rectum and behind the bladder. It is divided into four main sections: the top (fundus), middle (corpus), thin part (isthmus), and lower (cervix), which opens into the vagina.³

Types of uterine rupture during pregnancy

The lower part of the uterus, which includes the isthmus and inner cervical opening, develops later during pregnancy and has fewer muscle fibres. When labour starts, the upper part of the uterus contracts actively while the lower part stretches passively and becomes thinner, which leaves it more susceptible to rupture. It has been reported that these distinct changes in the upper and lower parts of the uterus during contractions might cause different types and results of uterine rupture during pregnancy.

Uterine rupture can happen in two ways:

• Scarred uterus: this means there's a previous cut or surgery on the uterus, like a Caesarean section. This type can lead to severe bleeding and needs immediate medical attention.
• Unscarred uterus: which means there's no previous surgery. This type of rupture is less common but can also cause serious complications for both the mother and the baby.⁴

Signs and symptoms

Uterine rupture symptoms may include:

• Abnormal fetal heart rate (foetal distress) 
• Elevated heart rate or low blood pressure in the pregnant individual
• Vaginal bleeding¹
• Incessant contractions or halted labour progress.⁵
• Acute Abdominal Pain: This is the most identified symptom.⁶

Causes of uterine rupture

Most uterine ruptures occur during labour, often in the same spot as a previous C-section scar. Contractions weaken the scar, making it more likely to tear, causing the baby to go into the abdomen. In the case of a previous C-section, the risk of uterine rupture is higher; your doctor may discuss a C-section to prevent any risk. Discuss your past pregnancies with your doctor to see if a vaginal birth after C-section (VBAC) is safe for you. In some cases, a C-section may be recommended to avoid uterine rupture.

Other causes of uterine rupture seen in unscarred uterine rupture include:

• Trauma
• A genetic condition that weakens the uterine wall
• Prolonged induction or augmentation of labour
• Overstretching of the uterine wall.⁷

Risk actors of uterine rupture

The reported incidence of uterine rupture in developed countries ranges from 0.22 to 0.5% among women who have had a prior caesarean section (CS). Among this population, previous classical incision (where the incision on the uterus is vertical), labour induction or augmentation, macrosomia, advanced maternal age, post-term delivery, small stature, and no prior vaginal birth increase the risk of uterine rupture. Maternal and perinatal problems such as major bleeding, infections, bladder injury, hysterectomy, and perinatal mortality are more likely to occur in cases of uterine rupture.⁸

These symptoms are often associated with specific risk factors such as:

• Uterine Scarring: Especially after a previous caesarean section (CS), particularly in women who didn't give birth naturally previously.
• Induction of Labor: Especially when prostaglandins are used.
• Short Time Since Previous CS: A short period (<12 or <24 months) after a previous CS.
• Augmentation of Labor: Using oxytocin.⁷
• Abnormal Foetal Position: The baby's position in the womb.
•  Excessive Amniotic Fluid: Having too much amniotic fluid.
• Placental Issues: Such as abruption and abnormally invasive placenta (e.g., placenta increta and placenta percreta).
• Connective Tissue Diseases: Conditions affecting the body's connective tissues.
• Adenomyosis: A condition where the tissue lining the uterus grows into the muscular wall.²
• Trauma: Any injuries or damage to the uterine area.
• Uterine Abnormalities: Structural issues with the uterus.^4,6

Diagnosis

• Clinical diagnosis: The majority of uterine rupture is diagnosed clinically based on the symptoms and signs seen. As it is an obstetric emergency, there may not be time for the results of the investigation.
• Laboratory test: Checking haemoglobin will help determine if there's heavy bleeding or signs of ongoing blood loss. These blood tests can assist in finding a small uterine tear.
• Cardiotocography (CTG) shows if the baby's heart rate has been slow for a long time and doesn't improve, abnormalities in the baby’s heart rate may indicate the need for urgent delivery.
• Ultrasound scans can be used to check problems that include uterine rupture with the uterus wall, a blood clot near a previous surgery scar, fluid in the belly, low amniotic fluid, or the baby's parts being outside the uterus.^1,2 Imaging cannot be used when there's a major rupture because the bleeding has to stop immediately, and the baby needs to be delivered.
• Laparotomy (CS): Is a surgical incision to confirm a uterine rupture in which case blood is found in the abdomen and the baby's body parts may be seen.¹

Complications

Uterine rupture can lead to serious problems for the mother, like maternal haemorrhage (bleeding), blood transfusion, hysterectomy, bladder injury, maternal death, as well as foetal prematurity, needing extra support after being born, or not surviving. These problems are worse when uterine rupture is not found and treated quickly because it's rare and unexpected.⁴

Management and treatment

Emergency Medical Care: Uterine rupture is a serious problem that needs quick attention. It often requires emergency C-section surgery to deliver the baby, and this is usually done under general anaesthesia. This helps manage bleeding and other issues.

Surgical Interventions: Uterine rupture means delivering the baby and treating the mother's bleeding right away. IV lines will need to be inserted, and blood tests will be taken; the mother will likely need to be taken to the operating theatre, and preparation for delivery of the baby will be undertaken. IV fluids will be administered, and a blood transfusion will be considered if blood loss is heavy. An arterial line helps check blood pressure more accurately and faster.

In mild cases, the uterus can be fixed, but if there's severe damage or instability, a hysterectomy (removal of the womb)  might be required. Around one in three women with uterine rupture have a hysterectomy.¹

FAQs

What differentiates placental abruption from uterine rupture?

Placental abruption occurs when the placenta separates from the uterus before delivery. This condition leads to symptoms like vaginal bleeding, sudden abdominal pain, and ongoing cramps. It can affect the baby's heart rate and often involves strong contractions. In severe cases, it can be life-threatening for both the mother and the baby. This condition shares common symptoms and risk factors with uterine rupture.¹

Is it possible to have more children after uterine rupture?

A lot of people go on to become pregnant again and give birth following a uterine rupture, however the risk of rupture increases and further pregnancy may not be recommended. If you've had a prior uterine rupture, you should discuss with your doctor what your options are. 

How can the risk of uterine rupture be reduced?

Sharing your full medical history and discussing risk factors with your provider can lower your risk of uterine rupture. If you've had previous C-sections, your provider might recommend scheduling a C-section to prevent labour and reduce uterine pressure. 

How common is uterine rupture?

In women who have already had a caesarean section, uterus rupture occurs roughly once in 300 deliveries. Those who have had more than one C-section are more likely to suffer a uterine rupture, which can occur in 9 of every 300 births.

Summary

Uterine rupture is a critical medical condition that occurs when the uterine wall tears, typically during labour. This can lead to severe complications for both the mother and the baby, including foetal distress and haemorrhage. Women with prior C-sections are at a higher risk, and in some cases, scheduled C-sections may be recommended to reduce this risk. Early detection and immediate medical intervention are essential in managing uterine rupture to ensure the safety of both mother and baby.