A uterine rupture during labor

Uterine rupture is a breach in the integrity of the uterine wall in any part during pregnancy or childbirth.

In the UK, uterine rupture is a relatively rare complication (1:1500 births), especially compared with other countries (1:100 in some parts of Africa). Maternal mortality is 5%, fetal mortality is 30%. In the UK, about 70% of uterine ruptures are due to failure of scars from a previous caesarean section (postoperative scars from lower uterine segment incisions rupture much less often than those from classic corporal incisions). Other predisposing factors include complicated labour in multiparous women, especially with the use of oxytocin; a history of cervical surgery; high forceps delivery, internal obstetric version and pelvic extraction.

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Risk factors for uterine rupture

The group of pregnant women who may experience uterine rupture during pregnancy and childbirth includes:

• pregnant women with a scar on the uterus, after surgery on the uterus (caesarean section, enucleation of myomatous nodes with suturing of the bed, enucleation of nodes with coagulation of the bed after endoscopic intervention, suturing of the uterine wall after perforation, tubectomy for intramural tubal pregnancy);
• pregnant women after multiple abortions, especially those complicated by inflammatory processes of the uterus;
• multiparous pregnant women;
• pregnant with a fetus of large body weight;
• pregnant women with pathological insertion of the head (frontal, high straight);
• pregnant women with abnormal fetal position (transverse, oblique);
• pregnant women with a narrow pelvis;
• pregnant women with a combination of a narrowed pelvis and a large fetal mass;
• pregnant women who were prescribed drugs that contract the uterus (oxytocin, prostaglandins) due to a scar on the uterus against the background of morphological changes in the wall of the uterus and the entire fetal bladder, polyhydramnios, multiple pregnancies, previous multiple abortions, childbirth;
• pregnant women with anatomical changes in the cervix due to the formation of scars after diathermocoagulation, cryodestruction, plastic surgery;
• pregnant women with uterine tumors that block the exit from the pelvis. If pregnant women with a scar on the uterus have had natural childbirth
• birth canal, a manual revision of the uterine cavity for its integrity immediately after the placenta is released is mandatory. During the revision of the uterus, special attention is paid to the examination of the left wall of the uterus, where ruptures are most often missed during a manual examination of the uterine cavity.

Signs and symptoms of uterine rupture

In most women, uterine rupture occurs during labor. Only occasionally can rupture occur before labor (usually due to scar divergence from a previous cesarean section). Some women experience slight soreness and tenderness over the uterus, while others experience severe pain. The intensity of vaginal bleeding also varies. It may even be slight (if most of the blood is released into the abdominal cavity). Other manifestations of uterine rupture include unexplained tachycardia and sudden development of shock in the mother, cessation of uterine contractions, disappearance of the presenting part from the pelvis, and fetal distress. In the postpartum period, uterine rupture is indicated by prolonged or persistent bleeding despite a well-contracted uterus, continued bleeding despite suturing of cervical ruptures; uterine rupture should be considered if the mother suddenly develops a state of shock.

Clinical symptoms of impending uterine rupture with disproportion between the fetus and the natal pelvis (clinically contracted pelvis) are excessive labor activity, insufficient relaxation of the uterus after contractions, sharply painful contractions, anxiety of the woman in labor, persistent pain syndrome between contractions in the lower segment of the uterus, pain during palpation of the lower segment of the uterus, absence or excessive configuration of the fetal head, abnormalities in insertion and presentation of the head (including posterior occipital presentation), premature, early rupture of membranes, increasing anhydrous interval, unproductive powerful activity with full or close to full dilation of the uterine os, involuntary pushing against the background of a high-positioned fetal head, edema of the cervix, vagina and external genitalia, birth tumor on the fetal head, which gradually fills the pelvic cavity, difficult urination; with prolonged labor - the appearance of blood in the urine; an hourglass-shaped uterus, deterioration of the fetus's condition, bloody discharge from the uterine cavity, a positive Henkel-Wasten symptom.

Histopathic uterine ruptures are characterized by the absence of clear symptoms and a "silent" course. The clinical symptoms of a threatening uterine rupture against the background of morphological changes in the myometrium (histopathic) include a pathological preliminary period, weakness of labor, no effect from labor stimulation, excessive labor after weakness of labor forces in response to labor stimulation therapy, possible pain syndrome, the appearance of constant pain and local soreness after contractions in the area of the scar on the uterus or lower segment, constant pain of unclear localization after contractions radiating to the sacrum, premature, early rupture of membranes, infections during childbirth (chorioamnionitis, endomyometritis), intrapartum hypoxia, antenatal fetal death.

Clinical symptoms of uterine rupture include cessation of labor, changes in the contours and shape of the uterus, pain syndrome (pain of various natures: aching, cramping in the lower abdomen and sacrum, sharp pain that occurs at the height of pushing, against the background of prolonged unproductive pushing with full opening of the uterine os, with a change in body position, distending pain in the abdomen; pain in the epigastric region with rupture of the uterus in the fundus, which is often accompanied by nausea and vomiting). 

During abdominal palpation, sharp general and local pain is noted; bloating, sharp pain during palpation and displacement of the uterus, the appearance of a sharply painful formation along the edge of the uterus or above the pubis (hematoma), a symptom of a blocked fundus of the uterus, the birth of the fetus in the abdominal cavity (palpation of its parts through the abdominal wall), symptoms of peritoneal irritation, external, internal or combined bleeding, increasing symptoms of hemorrhagic shock, intrauterine death of the fetus.

Symptoms of uterine rupture, which is diagnosed in the early postpartum period, include bleeding from the birth canal, no signs of placental separation, severe pain in all areas of the abdomen, severe pain when palpating the uterus, abdomen, nausea, vomiting, a symptom of a blocked fundus of the uterus, symptoms of hemorrhagic shock of varying degrees. When palpating the rib of the uterus, formations (hematoma) are determined. Hyperthermia is observed.

Classification of uterine ruptures

1. By pathogenesis:

Spontaneous rupture of the uterus:

• in case of morphological changes in the myometrium;
• in case of mechanical obstruction of the birth of the fetus;
• with a combination of morphological changes in the myometrium and mechanical obstruction of the birth of the fetus. 

Forced rupture of the uterus:

• clean (during vaginal operations to deliver babies, external trauma);
• mixed (with different combinations of gross intervention, morphological changes in the myometrium and mechanical obstruction of the birth of the fetus).

2. According to the clinical course:

• Risk of uterine rupture.
• Threatened uterine rupture.
• The rupture of the uterus that took place.

3. By the nature of the damage:

• Incomplete rupture of the uterus (not penetrating into the abdominal cavity).
• Complete rupture of the uterus (penetrating into the abdominal cavity).

4. By localization:

Rupture in the lower segment of the uterus:

• rupture of the anterior wall;
• lateral rupture;
• rupture of the posterior wall;
• separation of the uterus from the vaginal vaults.

Rupture in the body of the uterus.

• rupture of the anterior wall;
• rupture of the posterior wall.

Rupture of the fundus of the uterus.

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Management tactics for uterine rupture during childbirth

If there is a suspicion of uterine rupture during labor, a laparotomy should be performed, the baby should be removed by cesarean section, and the uterus should be revised during this operation.

Intravenous fluids are initiated for the mother. Shock is treated with urgent blood transfusion (6 bags). Preparations are made for laparotomy. The decision on the type of operation to be performed is made by the senior obstetrician; if the rupture is small, suturing may be performed (possibly with simultaneous tubal ligation); if the rupture involves the cervix or vagina, hysterectomy may be necessary. During the operation, special care must be taken to identify the ureters so as not to suture or ligate them. Postoperative antibiotics are prescribed, for example, ampicillin, 500 mg every 6 hours intravenously and netilmicin, 150 mg every 12 hours intravenously (if the patient does not have kidney pathology).

For pregnant women from the risk group, during the course of monitoring the pregnancy, a delivery plan is developed (it may change during the monitoring process) and before 38-39 weeks of pregnancy, a decision is made regarding the method of delivery (abdominal or through the natural birth canal).

In case of histopathic changes of the myometrium (scar on the uterus), women who do not have the same indications for the first caesarean section can give birth through the natural birth canal; history of one caesarean section, the previous caesarean section was performed in the lower segment of the uterus, previous births were through the natural birth canal; normal occipital presentation of the fetus; upon palpation through the anterior vaginal fornix, the area of the lower segment is uniform and painless; during ultrasound, the lower segment has a V-shape and a thickness of more than 4 mm, echo conductivity is the same as in other areas of the myometrium; there is a possibility of urgent operative delivery in case of complications, monitoring of labor is possible; consent for delivery through the natural birth canal has been obtained.

In such cases, childbirth is carried out under careful observation of the condition of the woman in labor (symptoms of a threatening rupture with histopathic changes in the myometrium).

In women with anatomical and functional inferiority of the uterine scar, delivery is performed by cesarean section at 40 weeks with a mature birth canal.

Symptoms of anatomical and functional inferiority of the scar include: pain in the lower segment, pain during palpation of the lower segment through the anterior vaginal fornix, its heterogeneity during ultrasound (thickness of the lower segment is less than 4 mm, different sound conductivity and thickness, balloon-like shape). 

Pregnant women at risk of uterine rupture during labor are closely monitored for the development of labor and the condition of the fetus. In the event of complications, the tactics of labor management are revised in favor of operative delivery.

If there are signs of a threatening uterine rupture, it is necessary to stop labor (tocolytics, narcotic or non-narcotic analgesics), transport the pregnant woman to the operating room, and immediately complete labor by surgery (delivery through the natural birth canal is possible if the fetus is presented in the plane of the narrow part or exit from the small pelvis).

A special feature of cesarean section in such cases is the removal of the uterus from the pelvic cavity for a detailed inspection of the integrity of its walls.

Treatment of a uterine rupture that has occurred consists of the following: the woman in labor is immediately transported to the operating room; if the woman's condition is very serious, the operating room is set up in the delivery room; anti-shock therapy is urgently administered with mobilization of the central veins, laparotomy and intervention adequate to the injury are performed. The pelvic organs and abdominal cavity are examined, the abdominal cavity is drained, infusion-transfusion therapy adequate to the amount of blood loss is provided, and hemocoagulation disorders are corrected.

The surgical intervention is performed in the following volume: suturing of the rupture, supravaginal amputation or extirpation of the uterus with or without the fallopian tubes. The volume of intervention depends on the size and location of the rupture, signs of infection, duration of the period after the rupture, level of blood loss, the woman's condition.

Indications for organ-preserving surgery are incomplete rupture of the uterus, small complete rupture, linear rupture with clear edges, absence of signs of infection, short anhydrous interval, preserved contractile function of the uterus.

Indications for supravaginal amputation of the uterus are fresh ruptures of its body with uneven crushed edges, moderate blood loss without signs of DIC syndrome and infection.

Extirpation of the uterus is performed in the presence of a rupture of its body or lower segment that has spread to the cervix with crushed edges, trauma to the vascular bundle, rupture of the cervix with transition to its body, and also in the case of impossibility to determine the lower angle of the wound.

In cases of chorioamnionitis, endometritis, and the presence of chronic infection, extirpation of the uterus along with the fallopian tubes is performed.

In all cases of surgical treatment for uterine rupture or during cesarean section for threatened uterine rupture, drainage of the abdominal cavity is performed. At the end of the operation, revision of the bladder, intestines, and ureters is mandatory.

If a bladder injury is suspected, 200 ml of a solution tinted with a contrast agent is injected into the bladder in order to determine whether it has entered the wound, monitoring the amount of solution removed from it (with an intact bladder - 200 ml).

If a ureteral injury is suspected, methylene blue is administered intravenously and its flow into the abdominal cavity or bladder is monitored using cystoscopy.

In case of massive blood loss, ligation of the internal iliac arteries is performed. In case of major trauma and significant blood loss, ligation of the internal iliac arteries is performed before the main part of the operation.

In the absence of an experienced specialist who can perform ligation of the internal iliac arteries, and the time required for this, the operation begins with clamping the main vessels along the edge of the uterus.

Drainage of the abdominal cavity is performed through an opening in the posterior fornix of the uterus after its extirpation and through counter-openings at the level of the iliac bones, when retroperitoneal hematomas form, and the peritoneum above them is not sutured.

In the postoperative period, anti-shock, infusion-transfusion, antibacterial therapy and prevention of thromboembolic complications are carried out.