Uterine rupture

Uterine rupture in pregnancy is a rare but disastrous situation. Numerous factors can increase the risk of uterine rupture, however, fortunately, even in high-risk groups, complete uterine rupture is low.

This phenomenon is remarkably rare for women who've never had a c-section or any surgery in the uterus, or who haven't experienced a previous rupture. Even though, mostly, the uterine ruptures are reported to happen during labor, they can also happen before the onset of labor or toward the second half of the third trimester.

What is uterine rupture?

Uterus has three layers. The inner lining, endometrium; the middle muscular layer, myometrium; and the outer layer, perimetrium. An uterine rupture, as the name implies, is the tearing of the uterus along its length and through the layers of the uterus. The amniotic sac surrounding the baby also ruptures in some cases, thereby, increasing the chances of the baby or placenta to thrust through the rupture into the abdominal cavity. There are three kinds of ruptures.

A complete or catastrophic rupture: In this type, the scar ruptures through all three layers of the uterine layers. It's a rare, but potentially serious complication which can take the life of the mother or child or both. It requires an immediate c-section

Incomplete rupture: Here, layers other than perimetrium undergo tearing. It is usually allied with the earlier lower segment C-section scar. This is also known as window, silent or occult rupture or an asymptomatic separation.

Uterine scar dehiscence:  This type of uterine rupture is seen in women who underwent a scheduled repeat C- sections or when women had a VBAC. Here, the scar only stretches or partially separated. As the fetal membrane remains intact, this type of rupture is relatively harmless as the fetus is not expelled into the peritoneal cavity.

When it comes to uterine rupture, this type is relatively common and rarely pose risks for mother or baby. They occur in about 1% to 2% of mothers with one low transverse scar. They usually do not need medical treatment as it resolves itself.

What increases the chances of uterine rupture?

Previous surgery in the uterus: In the majority of the cases reported, the uterine rupture takes place at the location of a scar from a previous c-section. The same may be true for women who underwent other kinds of uterine surgery, like surgery to remove fibroid or to rectify a deformed uterus.

Obstructed labor: Obstructed labor, is a condition in which the baby gets stuck in the birth canal, unable to get out through the vagina, even though the uterus is contracting normally. Similarly, prolonged labor with a big baby can also bring about uterine rupture.

Trauma to the uterus: Any external direct trauma to the uterus, like vehicle accidents, can result in uterine rupture.

Overly distended uterus: An excessively distended uterus, either due to too much amniotic fluid (hydramnios) or multiple pregnancies can bring about uterine rupture.

Induced labor: In some cases, induction of labor can lead to uterine rupture if the induced prostaglandins gives rise to too frequent and forceful contractions

Placenta accreta: Placenta accreta, a condition that occurs where the placenta attaches itself too deeply into the wall of the uterus,  is a rare obstetric condition that mainly occurs in the third trimester. Uterine rupture is a major consequence of this condition.

Use of rotational forceps: Usage of rotational forceps during the instrumental delivery can bring about uterine rupture.

What are the symptoms of uterine rupture?

  • Excessive and unusual vaginal bleeding
  • Sharp pain between contractions
  • Sharp onset of pain and tenderness in the previous scar
  • Contractions that slow down or become less intense
  • Unusual abdominal pain
  • Recession of the fetal head (baby's head moving back up into the birth canal)
  • Baby's head is bulging under the pubic bone, indicating the head is outside the uterus
  • The uterus losing muscle tone
  • Rapid heart rate and abnormally low blood pressure in the mother

What are the complications of uterine rupture?

  • Increases the chances of postoperative infection.
  • It can severely damage the ureter.
  • It can bring about amniotic fluid embolism, a condition in which amniotic fluid, enters the bloodstream of the mother to trigger serious consequence.
  • Uterine rupture puts the baby at risk of oxygen deprivation and can subject the baby to severe and permanent health issues and even cost baby's life.

Treating uterine rupture:

When the uterine rupture happens during the labor, an immediate C-section is performed to deliver the baby. If the damage to the woman's uterus is extensive and the bleeding can't be controlled, she'll need a hysterectomy. Around 14-33% of women with uterine rupture is found to require an emergency hysterectomy. Otherwise, her uterus will be repaired. Either way, however, the mother usually loses a lot of blood and requires a transfusion.