Reasons for uterine rupture
Release time : 05/09/2025 09:30:02
The reasons for uterine rupture should be understood by every expectant mother. It is essential to prepare and protect the baby's health, as well as one's own, avoiding unnecessary illnesses.
Take a look, this is important knowledge for expectant mothers! The cause of uterine rupture often occurs in labor, in older women with multiple pregnancies, and in women who have had previous cesarean sections or have sustained injuries to the uterus.
According to the cause of rupture, it can be divided into non-scar uterine rupture and scar uterine rupture.
The main reasons are as follows: (1)Obstructive dystocia: Obvious pelvic stenosis, cephalopelvic disproportion, soft birth canal deformity, pelvic tumors and abnormal fetal position and other factors hinder the decline of fetal presentation. The uterus contracts in order to overcome resistance, and the lower segment of the uterus is forced to lengthen and thin. Eventually uterine rupture occurs.
This type of uterine rupture is the most common type of uterine rupture, and most of the rupture occurs in the lower segment of the uterus.
(2) Uterine scar rupture: The causes of uterine scar rupture mainly include cesarean section, myomectomy, repair of uterine rupture or perforation, and correction of uterine deformity.
The cause of rupture is the mechanical stretching of the pregnant uterus, leading to rupture at the scar or damage to the uterine scar tissue, placental implantation, penetration of the placenta, and spontaneous uterine rupture.
In recent years, there has been a rapid increase in cesarean sections. The incidence of uterine rupture following a vertical incision in the fundus of the uterus during a repeat pregnancy is higher than that of a transverse incision at the lower segment. This may be attributed not only to the differences in anatomical properties between the vertical and transverse incisions but also to the role of infection factors. Patients who underwent a vertical incision for a cesarean section typically experienced prolonged labor with multiple vaginal examinations, increasing their risk of infection.
(3) Abuse of uterotonics: This includes substances that stimulate uterine contractions, such as the most commonly used prostaglandins (oxytocin) and mifepristone, a newer uterotonic. Reports on cases of uterine rupture caused by mifepristone are increasingly common.
The primary causes include excessive drug dosage or administration rate, immature cervix, incorrect fetal position, obstructed labor, and inadequate observation of the labor process during medication.
Vaginal delivery surgery injury: Forced forceps delivery or pelvic traction due to incomplete dilation of the cervix, resulting in severe laceration and extension up to the lower segment of the uterus.
Omission of transverse inversion, uterine detorsion, and partial artificial detachment of the placenta can all lead to uterine rupture due to improper procedures.
Uterine malformations and dysplastic uterine wall, the most common being the bicornuate or unicornuate uterus.
Lesions of the uterus itself: polyparia, history of multiple curettage, history of infectious abortion, history of uterine cavity infection, history of artificial detachment of placenta, history of hydatidiform mole, etc.
Due to the above factors, the endometrium and even the muscle wall are damaged, the placenta is implanted or penetrated after pregnancy, and ultimately the uterus is ruptured.
2. Classification The classification of uterine rupture is mainly classified according to factors such as the cause of rupture, rupture time, rupture location and degree of rupture as follows: - Classified according to the causes of rupture, it can be divided into spontaneous rupture and traumatic rupture. - Classification according to rupture time, it can be divided into early rupture and late rupture. - Classification according to the rupture location, it can be divided into anterior wall rupture, posterior wall rupture and sidewall rupture. - Classified according to the degree of rupture, it can be divided into complete rupture and incomplete rupture.
(1)Classification according to the causes of rupture: ① Spontaneous uterine rupture mostly occurs before delivery, and is common in scar uterus and uterine dysplasia such as bicornuate uterus.
② Traumatic uterine rupture mostly occurs during labor.
(2)Classified according to the time of rupture, ① Uterine rupture during pregnancy is common in scar uterus and uterine dysplasia.
② Uterine rupture during childbirth is most common in multipara. The reasons are mostly obstructive dystocia or surgical trauma or improper use of oxytocin. Most uterine ruptures occur during this period.
(3) According to the location of uterine rupture: (1) Uterine body rupture, which is commonly seen in scarred uterus, placental implantation, and underdeveloped uterus.
2. Uterine lower segment rupture is commonly observed in obstructed labor and unsuitable vaginal delivery leading to a cervical tear extending upwards.
(4) According to the degree of uterine rupture: ① Complete uterine rupture: The uterine wall is completely torn open, the uterine cavity communicates with the peritoneal cavity, and the fetus and placenta can be trapped at the site of the uterine rupture or enter the peritoneal cavity. If the gestational age is small, the placenta and amniotic sac encapsulate the fetus completely and enter the peritoneal cavity.
2. Incomplete uterine rupture: Partial or complete rupture of the uterine muscle wall, with the serosa intact.
Commonly, uterine incision at the lower segment results in a broad ligament hematoma, also known as broad ligament uterine rupture.
Uterine rupture refers to the tearing of the uterine body or lower segment during labor or pregnancy, which is a severe complication in obstetrics and threatens mother and child's life.
The main causes of death are bleeding, infection, and shock.
With the improvement of obstetric quality, the establishment and perfection of maternal and child health care network in urban and rural areas, the incidence rate has been significantly lower.
City hospitals are rarely seen, while rural remote areas frequently experience these incidents.
Uterine rupture is divided into two types: (1) Complete uterine rupture: The entire uterine wall breaks open, with amniotic fluid, placenta, and part or all of the fetus being pushed into the abdominal cavity.
Upon rupture, the parturient suddenly feels a tearing pain in her abdomen, followed by an intermission of contractions, and then the abdominal pain suddenly diminishes.
Subsequently, as amniotic fluid, fetal tissue, and blood enter the abdominal cavity, persistent pelvic pain occurs. The parturient may exhibit symptoms of shock, such as pallor, cold sweats, shallow respiration, rapid pulse, and a decrease in blood pressure. There may be vaginal bleeding, varying in amount.
The presenting part of the fetus disappears, and the dilated cervix retracts during descent. When a uterine wall ruptures, the incision may extend anteriorly to involve the bladder.
Abdominal examination reveals tenderness and rebound pain throughout the abdomen. The fetus's limbs can be palpated clearly beneath the abdominal wall. Fetal heart sounds are absent, and the uterus cannot be palpated distinctly. Sometimes, a smaller uterine cavity can be felt on one side of the fetus. If there is significant intra-abdominal bleeding, mobile fluid can be palpated with percussion.
A vaginal examination will reveal a rising fetal presentation, the cervix is narrowed, and sometimes an incision can be palpated within the uterine cavity.
(2)Incomplete rupture: The myometrium is partially or completely torn, but the serosa remains intact. The uterine cavity remains separated from the peritoneum, and the fetus remains within the uterus.
Should a tear occur in the lower segment of the uterine side wall, it may form a hematoma between the broad ligament's two lobes. Should the uterine artery be torn, serious extraperitoneal bleeding and shock can result.
Abdominal examination reveals that the uterus remains in its original shape, with significant tenderness upon palpation. A gradually enlarged hematoma can be palpated on one side of the abdomen.
The broad ligament hematoma can extend upwards, thus becoming a retroperitoneal hematoma.
Should bleeding persist, the hematoma can rupture through the serosa, leading to a complete uterine rupture.
Symptoms of uterine rupture: Uterine rupture can occur during the late stages of pregnancy before labor, but most commonly occurs during the process of labor when delivery is difficult. This is characterized by prolonged labor with a fetus or the presenting part unable to enter the pelvis or being obstructed above the level of the coccyx.
Uterine rupture can be divided into pre-rupture and rupture stages.
1. In the process of labor, when the fetal presenting part is obstructed and there are strong contractions, the lower segment of the uterus gradually thins out due to the powerful contractions while the uterus body becomes thicker and shorter. This results in a noticeable ring-shaped depression between them, which will gradually rise to the level of the umbilicus or above. This condition is known as the pathological retraction ring.
At this time, the lower segment prominence is present with significant tenderness. The uterine ligaments are extremely tense, and a palpable mass can be clearly felt with tenderness.
The parturient complains of severe abdominal pain, restlessness, distress, and calls for help, with rapid pulse and breathing.
Due to the compression of the fetal presenting part against the bladder, congestion occurs, leading to difficulty in urinating and the formation of hematuria.
Due to excessive uterine contractions, fetal blood supply is obstructed, fetal heart rate changes or becomes inaudible.
If this condition is not resolved immediately, the uterus will soon rupture at and below the pathological contraction ring.
2. Uterine rupture can be divided into two types: complete uterine rupture and incomplete uterine rupture according to the degree of rupture.
(1) Complete uterine rupture: refers to the full-thickness rupture of the uterine wall, allowing the uterine cavity to communicate with the abdominal cavity.
The moment the uterus completely ruptures, the pregnant woman often feels tearing and severe abdominal pain. Then the contraction of the uterus disappears and the pain is relieved. However, as blood, amniotic fluid and the fetus enter the abdominal cavity, she soon feels pain in the whole abdomen again. The pulse is accelerated and weak, and the breathing is rapid., blood pressure drops.
During examination, there was tenderness and rebound pain in the whole abdomen. The carcass could be clearly touched under the abdominal wall. The uterus shrank to the side of the fetus. The fetal heart disappeared. There may be blood flowing out of the vagina. The amount may be more or less.
The presentation of the fetus during the process of exposure or descent disappears (the fetus enters the abdominal cavity), and the once dilated uterine orifice can retract.
When the anterior wall of the uterus ruptures, the laceration can extend anteriorly to rupture the bladder.
Should a diagnosis of uterine rupture be made, there is no need to proceed with an examination of the uterine rupture site through the vagina.
If the uterine rupture was caused by the injection of oxytocin, the patient felt strong contractions in the uterus and suddenly severe pain, the presenting part moved up and disappeared at once.
Uterine scar rupture can occur in the late stages of pregnancy, but more frequently during childbirth.
At the onset, there is slight abdominal pain, and tenderness is palpable at the scar site of the uterine incision. This suggests that there may be a rupture of the uterine scar, but the membranes are not ruptured, and fetal heart rate is normal.
If the cesarean section is not performed immediately, the fetus may enter the abdominal cavity through the ruptured opening, producing symptoms and signs similar to those of an uterine rupture.
(2) Incomplete uterine rupture: This refers to uterine myometrium that has completely or partially ruptured, with the serosa layer not breached, and the intrauterine cavity and peritoneal cavity not communicating, with the fetus and its ancillary structures still within the intrauterine cavity.
Abdominal examination reveals tenderness at the site of partial uterine rupture. If the rupture occurs between the two lobes of the broad ligament, it may lead to a hematoma within the broad ligament. At this time, a gradually enlarged and tender mass can be palpated on the side of the uterus.
The fetal heartbeat is often irregular.
What to do with a ruptured uterus? When threatened uterine rupture is discovered, effective measures must be taken immediately to inhibit uterine contraction, such as general anesthesia with ether, intramuscular injection of 100mg of meperidine, etc., to alleviate the process of uterine rupture.
It is best to perform cesarean section as soon as possible, and pay attention to check whether the uterus has ruptured during the operation.
If the fetus is not delivered, even if the fetus is still born, the fetus should not be delivered through the vagina first. This will widen the tear, increase bleeding, and promote the spread of infection. The stillbirth should be removed quickly by laparotomy, depending on the patient's status, the location of the laceration, the degree of infection and whether the patient has children. If the uterine tear is easy to suture, the infection is not serious, and the patient's condition is poor, the tear can be repaired and sutured. If there are children, the fallopian tubes can be ligated, and if there are no children, their fertility function can be preserved.
Otherwise, total or subtotal hysterectomy may be performed.
If the lower segment of the uterus is ruptured, attention should be paid to the bladder, ureter, cervix and vagina. If there is any damage, it should be repaired in time.
Uterine rupture is often accompanied by severe bleeding and infection. Blood transfusions, infusion, sodium lactate should be given before surgery, active anti-shock treatment should be given, and a large dose of broad-spectrum antibiotics should be used to control infection during and after surgery.
The hazards of uterine rupture include: 1. Bleeding. Uterine rupture usually manifests as massive bleeding, which is divided into internal bleeding, external bleeding or mixed bleeding.
Internal bleeding refers to the accumulation of bleeding in the broad ligament or abdominal cavity, resulting in broad ligament hematoma or hemoperitoneum.
External bleeding refers to bleeding that drains from the vagina.
Bleeding sites of uterine rupture usually include: uterine and soft birth canal rupture and placental dissection.
Bleeding from the uterus and soft birth canal usually requires damage to the major blood vessels in the area. If the soft birth canal injury does not damage the major blood vessels, it usually does not show as major or active bleeding.
The bleeding at the placental separation site is related to the degree of placental separation and the strength of uterine contraction. If the placenta is not completely separated or does not exit the uterus, it affects uterine contraction, resulting in severe hemorrhage.
Conversely, if the placenta has completely detached and been expelled from the uterine cavity, with good uterine contraction, there will be minimal active bleeding at the site of the detachment.
The bleeding described above refers to preoperative and postoperative bleeding. The primary causes include hemorrhage following the removal of a broad ligament hematoma, or bleeding from the wound after DIC treatment, or persistent bleeding from the uterus after conservative management.
Bleeding not only leads to hemorrhagic shock but also due to the hypercoagulable state of parturients, excessive bleeding and long-term shock, DIC may occur.
2. Following uterine rupture, the areas prone to infection primarily include the pelvis, abdominal cavity, retroperitoneal space, and the vaginal canal.
The main causes of infection include: the pouch and broad ligament communicate with the uterine cavity and vagina, allowing bacteria to enter.
Following a uterine rupture, severe hemorrhage, anemia or DIC, and compromised immunity, susceptibility to infection.
Abdominal or pelvic blood accumulation, or extraperitoneal blood accumulation, is prone to infection.
Hysterectomy or repair after uterine rupture is performed under bacterial conditions.
There may be more vaginal procedures during diagnosis after uterine rupture.
Long-term uterine rupture is more likely to lead to various infections in multiple locations.
In addition, an infection worth mentioning is respiratory tract infection, which can cause infection. Excessive shock time is related to impaired sputum discharge and defense mechanisms of the normal respiratory tract. At the same time, factors such as aspiration cannot be excluded.
3. Injuries that cause damage to the birth canal and other abdominal and pelvic organs and tissues and rupture of the uterus include injuries before and after surgical intervention.
Injuries before surgical intervention include various injuries to the uterine body, lower uterus, cervix and vagina. There may also be primary bladder injury caused by compression of the fetal head.
Patients with uterine rupture often have extensive damage during the diagnosis process and surgical treatment, sometimes exceeding the primary injury.
During the diagnostic process, excessive unnecessary vaginal manipulation or examinations may exacerbate damage to the birth canal.
Exploratory laparotomy, which involves cleaning up blood clots or removing the fetus, placenta, and membranes, can lead to intestinal or omental injury if not performed properly.
Cleaning of broad ligament hematoma may cause injury to the pelvic vessels, ureters, and bladder.
Prolonged uterine rupture results in more severe damage to abdominal organs.
4. Impact on the fetus The impact on the fetus after uterine rupture is mainly caused by different times and varying degrees of bleeding, and most fetuses die.
The perinatal morbidity and mortality rates of surviving fetuses are significantly increased, and long-term complications are also significantly increased.
* The medical part covered in this article is for reading and reference only.
If you feel unwell, it is recommended to seek medical treatment immediately, based on offline face-to-face diagnosis, medical diagnosis and treatment.