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Emergency exploratory laparotomy with cesarean delivery accompanied by fluid and blood transfusion are indicated for the management of uterine rupture. Depending on the nature of the rupture and the condition of the patient, the uterus may be either repaired or removed (cesarean hysterectomy). Delay in management places both mother and child at significant risk.
A uterine scar from a previous cesarean section is the most common risk factor. (In one review, 52% had previous cesarean scars.) Other forms of uterine surgery that result in full-thickness incisions (such as a myomectomy), dysfunctional labor, labor augmentation by oxytocin or prostaglandins, and high parity may also set the stage for uterine rupture. In 2006, an extremely rare case of uterine rupture in a first pregnancy with no risk factors was reported.
The most common cause is the mismanagement of 3rd stage of labor, such as:
- Fundal pressure
- Excess cord traction during the 3rd stage of labor
Other natural causes can be:
- Uterine weakness, congenital or not
- Precipitate delivery
- Short umbilical cord
It is more common in multiple gestation than in singleton pregnancies.
The incidence is of 1/2000 pregnancies.
AS has a reported incidence of 25% of D&Cs performed 1–4 weeks post-partum, up to 30.9% of D&Cs performed for missed miscarriages and 6.4% of D&Cs performed for incomplete miscarriages. In another study, 40% of patients who underwent repeated D&C for retained products of conception after missed miscarriage or retained placenta developed AS.
In the case of missed miscarriages, the time period between fetal demise and curettage may increase the likelihood of adhesion formation due to fibroblastic activity of the remaining tissue.
The risk of AS also increases with the number of procedures: one study estimated the risk to be 16% after one D&C and 32% after 3 or more D&Cs. However, a single curettage often underlies the condition.
In an attempts to estimate the prevalence of AS in the general population, it was found in 1.5% of women undergoing hysterosalpingography HSG, and between 5 and 39% of women with recurrent miscarriage.
After miscarriage, a review estimated the prevalence of AS to be approximately 20% (95% confidence interval: 13% to 28%).
Many factors can contribute to the loss of uterine muscle tone, including:
- overdistention of the uterus
- multiple gestations
- polyhydramnios
- fetal macrosomia
- prolonged labor
- oxytocin augmentation of labor
- grand multiparity (having given birth 5 or more times)
- precipitous labor (labor lasting less than 3 hours)
- magnesium sulfate treatment of preeclampsia
- chorioamnionitis
- halogenated anesthetics
- uterine leiomyomata
- full bladder
- retained colyledon, placental fragments
- placenta previa
- placental abruption
- constriction ring
- incomplete separation of the placenta
Uterine inversion is often associated with significant Post-partum hemorrhage. Traditionally it was thought that it presented with haemodynamic shock "out of proportion" with blood loss, however blood loss has often been underestimated. The parasympathetic effect of traction on the uterine ligaments may cause bradycardia.
The occurrence of couvelaire uterus can be prevented by prevention of abruptio placentae. This include proper management of hypertensive states of pregnancy; treatment of maternal diseases like diabetes mellitus, and other collagen disease complicating pregnancy; prevention of trauma during pregnancy; mothers should also avoid smoking or consumption of alcohol during pregnancy.
The extent of adhesion formation is critical. Mild to moderate adhesions can usually be treated with success. Extensive obliteration of the uterine cavity or fallopian tube openings (ostia) and deep endometrial or myometrial trauma may require several surgical interventions and/or hormone therapy or even be uncorrectable. If the uterine cavity is adhesion free but the ostia remain obliterated, IVF remains an option. If the uterus has been irreparably damaged, surrogacy or adoption may be the only options.
Depending on the degree of severity, AS may result in infertility, repeated miscarriages, pain from trapped blood, and future obstetric complications If left untreated, the obstruction of menstrual flow resulting from adhesions can lead to endometriosis in some cases.
Patients who carry a pregnancy even after treatment of IUA may have an increased risk of having abnormal placentation including placenta accreta where the placenta invades the uterus more deeply, leading to complications in placental separation after delivery. Premature delivery, second-trimester pregnancy loss, and uterine rupture are other reported complications. They may also develop incompetent cervix where the cervix can no longer support the growing weight of the fetus, the pressure causes the placenta to rupture and the mother goes into premature labour. Cerclage is a surgical stitch which helps support the cervix if needed.
Pregnancy and live birth rate has been reported to be related to the initial severity of the adhesions with 93, 78, and 57% pregnancies achieved after treatment of mild, moderate and severe adhesions, respectively and resulting in 81, 66, and 32% live birth rates, respectively. The overall pregnancy rate after adhesiolysis was 60% and the live birth rate was 38.9% according to one study.
Age is another factor contributing to fertility outcomes after treatment of AS. For women under 35 years of age treated for severe adhesions, pregnancy rates were 66.6% compared to 23.5% in women older than 35.
Interstitial pregnancies account for 2–4% of all tubal pregnancies, or for 1 in 2,500 to 5,000 live births. About one in fifty women with an interstitial pregnancy dies. Patients with an interstitial pregnancies have a 7-times higher mortality than those with ectopics in general. With the growing use of assisted reproductive technologies, the incidence of interstitial pregnancy is rising.
An important risk factor for placenta accreta is placenta previa in the presence of a uterine scar. Placenta previa is an independent risk factor for placenta accreta. Additional reported risk factors for placenta accreta include maternal age and multiparity, other prior uterine surgery, prior uterine curettage, uterine irradiation, endometrial ablation, Asherman syndrome, uterine leiomyomata, uterine anomalies, hypertensive disorders of pregnancy, and smoking.
The condition is increased in incidence by the presence of scar tissue i.e. Asherman's syndrome usually from past uterine surgery, especially from a past dilation and curettage, (which is used for many indications including miscarriage, termination, and postpartum hemorrhage), myomectomy, or caesarean section. A thin decidua can also be a contributing factor to such trophoblastic invasion. Some studies suggest that the rate of incidence is higher when the fetus is female. Other risk factors include low-lying placenta, anterior placenta, congenital or acquired uterine defects (such as uterine septa), leiomyoma, ectopic implantation of placenta (including cornual pregnancy).
Pregnant women above 35 years of age who have had a Caesarian section and now have a placenta previa overlying the uterine scar have a 40% chance of placenta accreta.
True cervical pregnancies tend to abort; if, however, the pregnancy is located higher in the canal and the placenta finds support in the uterine cavity it can go past the first trimester. With the placenta being implanted abnormally extensive vaginal bleeding can be expected at time of delivery and placental removal. While early cervical pregnancies may abort spontaneously or can be managed with excision, D&C, suturing, electrocautery, and tamponading, by medication such as methotrexate, and/or by uterine artery embolization, a more advanced pregnancy may require a hysterectomy to control bleeding. The more advanced the pregnancy the higher the risk for a major bleeding necessitating a hysterectomy.
On a very rare occasion, a cervical pregnancy results in the birth of a live baby, typically the pregnancy is in the upper part of the cervical canal and manages to extend into the lower part of the uterine cavity.
A cervical pregnancy can develop together with a normal intrauterine pregnancy; such a heterotopic pregnancy will call for expert management as to not to endanger the intrauterine pregnancy.
In the United States, uterus didelphys is reported to occur in 0.1–0.5% of women. It is difficult to know the exact occurrence of this anomaly, as it may go undetected in the absence of medical and reproductive complications.
A number of twin gestations have occurred where each uterus carried its pregnancy separately. A recent example occurred on February 26, 2009, when Sarah Reinfelder of Sault Ste. Marie, Michigan delivered two healthy, although seven weeks premature, infants by cesarean section at Marquette General Hospital. It is possible that the deliveries occur at different times, thus the delivery interval could be days or even weeks.
Methods of measuring blood loss associated with childbirth vary, complicating comparison of prevalence rates. A systematic review reported the highest rates of PPH in Africa (27.5%), and the lowest in Oceania (7.2%), with an overall rate globally of 10.8%. The rate in both Europe and North America was around 13%. The rate is higher for multiple pregnancies (32.4% compared with 10.6% for singletons), and for first-time mothers (12.9% compared with 10.0% for women in subsequent pregnancies). The overall rate of severe PPH (>1000 ml) was much lower at an overall rate of 2.8%, again with the highest rate in Africa (5.1%).
The reported incidence of placenta accreta has increased from approximately 0.8 per 1000 deliveries in the 1980s to 3 per 1000 deliveries in the past decade.
Incidence has been increasing with increased rates of Caesarean deliveries, with rates of 1 in 4,027 pregnancies in the 1970s, 1 in 2,510 in the 1980s, and 1 in 533 for 1982–2002. In 2002, ACOG estimated that incidence has increased 10-fold over the past 50 years. The risk of placenta accreta in future deliveries after Caesarian section is 0.4-0.8%. For patients with placenta previa, risk increases with number of previous Caesarean sections, with rates of 3%, 11%, 40%, 61%, and 67% for the first, second, third, fourth, and fifth or greater number of Caesarean sections.
Most studies of uterine malformations are based on populations of women who have experienced a pregnancy loss and thus do not address the issue of the prevalence in the general population. A screening study by Woelfer et al. of women without a history of reproductive problems found that about 5% of women had an arcuate uterus when they defined an arcuate uterus any fundal protrusion into the cavity that had an apical angle of more than 90 degrees. Accordingly, it was the most common uterine anomaly, followed by septate uterus (3%) and bicornuate uterus (0.5%).
The fetus may be compromised if there is prolonged delivery because of the non-contractile uterus; severe bleeding may cause hypovolemic shock in the mother.
Causes of postpartum hemorrhage are uterine atony, trauma, retained placenta, and coagulopathy, commonly referred to as the "four Ts":
- Tone: uterine atony is the inability of the uterus to contract and may lead to continuous bleeding. Retained placental tissue and infection may contribute to uterine atony. Uterine atony is the most common cause of postpartum hemorrhage.
- Trauma: Injury to the birth canal which includes the uterus, cervix, vagina and the perineum which can happen even if the delivery is monitored properly. The bleeding is substantial as all these organs become more vascular during pregnancy.
- Tissue: retention of tissue from the placenta or fetus may lead to bleeding.
- Thrombin: a bleeding disorder occurs when there is a failure of clotting, such as with diseases known as coagulopathies.
Patients with an ectopic pregnancy are generally at higher risk for a recurrence, however, there are no specific data for patients with an interstitial pregnancy. When a new pregnancy is diagnosed it is important to monitor the pregnancy by transvaginal sonography to assure that is it properly located, and that the surgically repaired area remains intact. Cesarean delivery is recommended to avoid uterine rupture during labor.
Although the risk of placental abruption cannot be eliminated, it can be reduced. Avoiding tobacco, alcohol and cocaine during pregnancy decreases the risk. Staying away from activities which have a high risk of physical trauma is also important. Women who have high blood pressure or who have had a previous placental abruption and want to conceive must be closely supervised by a doctor.
The risk of placental abruption can be reduced by maintaining a good diet including taking folic acid, regular sleep patterns and correction of pregnancy-induced hypertension.
It is crucial for women to be made aware of the signs of placental abruption, such as vaginal bleeding, and that if they experience such symptoms they must get into contact with their health care provider/the hospital "without any delay".
The prognosis of this complication depends on whether treatment is received by the patient, on the quality of treatment, and on the severity of the abruption. Outcomes for the baby also depend on the gestational age.
In the Western world, maternal deaths due to placental abruption are rare. The fetal prognosis is worse than the maternal prognosis; approximately 12% of fetuses affected by placental abruption die. 77% of fetuses that die from placental abruption die before birth; the remainder die due to complications of preterm birth.
Without any form of medical intervention, as often happens in many parts of the world, placental abruption has a high maternal mortality rate.
During labor the shoulder will be wedged into the pelvis and the head lie in one iliac fossa, the breech in the other. With further uterine contractions the baby suffocates. The uterus continues to try to expel the impacted fetus and as its retraction ring rises, the musculature in the lower segments thins out leading eventually to a uterine rupture and the death of the mother. Impacted shoulder presentations contribute to maternal mortality. Obviously a cesarean section should be performed before the baby has died, but even when the baby has died or impaction has occurred, C/S is the method of choice of delivery, as alternative methods of delivery are potentially too traumatic for the mother. If the baby is preterm or macerated and very small a spontaneous delivery has been observed.
Uterine atony is a loss of tone in the uterine musculature. Normally, contraction of the uterine muscles during labor compresses the blood vessels and reduces flow, thereby increasing the likelihood of coagulation and preventing hemorrhage. A lack of uterine muscle contraction, however, can lead to an acute hemorrhage, as the uterine blood vessels are not sufficiently compressed. Clinically, 75-80% of postpartum hemorrhages are due to uterine atony.
The pathogenesis of RLP is varied. Although very common during pregnancy, non-gestating women can also experience RLP. The most common causes of RLP are as follows:
- RLP may be caused by a spasm or cramp when the ligament contracts involuntarily. The ligament pulls on nerve fibers and sensitive structures of the female reproductive system. Since the uterus tends to be oriented towards the right side of the body, the pain is also often felt on the right side. This leads to frequent confusion with appendicitis.
- During pregnancy, the uterus expands to accommodate the growing fetus. This increase in size and weight of the uterus puts stress on the ligament that holds it, causing it to stretch. During physical exertion or sudden movements, the ligament is overly stretched, causing pain.
- Varicosities, e.g. enlargement of the blood vessels of the round ligament can occur during pregnancy, causing pain and swelling. The varicocoele starts at the veins draining the round ligament and the inguinal canal and is associated with engorgement of the veins of the ovaries and the pelvis during pregnancy.
- Endometriosis that infiltrates or borders the uterine round ligament can cause RLP in fertile, non-gestating women.
- Other pathologies that involve the uterine round ligament can cause RLP.
In many cases, RLP is confused with other conditions that cause abdominal pain. Described below are some problematic diagnoses related to RLP.
- RLP and appendicitis
A 22-year-old pregnant woman presenting abdominal pains was initially diagnosed with RLP and was discharged. Subsequent symptoms and further tests revealed acute non-perforated appendicitis that required surgery. Appendectomy was successful but premature labor occurred 7 days after discharge, leading to spontaneous abortion.
- RLP and inguinal hernia
Several cases of varicosity, of the round ligament during pregnancy leading to RLP have been reported although they were frequently misdiagnosed as inguinal hernia.
In one case, a woman in the 28th week of gestation developed a lump in the left pubic area. The swelling was prominent when standing but not in the supine position and has a cough impulse. Ultrasonography revealed varicosities on the uterine round ligament.
In another case, a woman at 22 weeks gestation was diagnosed with inguinal hernia and underwent surgery. Explorative surgery did not locate a hernia but revealed varicosities of the round ligament. Resection of the uterine ligament was successfully performed and no perinatal and postpartum complications were reported.
- Postpartum RLP
Several cases of postpartum RLP have been reported. In one case, a 27-year-old woman presented with abdominal pain 24 hours after normal vaginal delivery. Another case was that of a 29-year-old woman who presented with RLP 3 days after delivery. In both cases, initial diagnosis was inguinal hernia. In the first case, emergency surgery did not locate any hernia but found the round ligament of the uterus to be edematous and filled with thrombosed varicose veins. The thrombosed part was excised and the patient recovered without sequelae.
Another case report described a 37-year-old woman presenting with inguinal mass 6 days after normal vaginal delivery. CT and MRI revealed thrombosed blood vessels along the inguinal course of the uterine round ligament that extended towards the labia majora.
- RLP and endometriosis
Several cases of inguinal endometriosis, that infiltrates the round ligament of the uterus have been reported in fertile, non-pregnant women. In the majority of these cases, diagnosis was problematic. In some cases, definitive diagnosis of round ligament endometriosis was only possible during exploratory surgery.
- RLP and myoma
Cases of myoma-like growth occurring on the uterine round ligament have been reported.
- RLP and IVF
Gonadotropin stimulation during in vitro fertilization can induce cyst development in certain parts of the female reproductive system. A case report documented the development of a mesothelial cyst on the uterine round ligament of a woman after IVF stimulation.