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Frequently asked questions about Malposition of Uterus Mal-position of the Uterus IntroductionIntermittent myometrial contractions and changes in uterine position are normal during pregnancy. Infrequently, various obstetric complications result from uterine malpositioning (retroversion or incarceration), inversion, and, in rare cases, prolapse, torsion, or herniation. Special devices and many surgical techniques were developed to either reposition the uterus or to hold it in its presumed correct location. These operations and manipulations were believed to be necessary for the maintenance or restoration of normal functioning. Uterine Retroversion or Incarceration Frequency During early pregnancy, uterine retroversion is a normal positional variant. Typically, first-trimester retroversion is intermittently present 10-20% of the time. If retroversion persists into the mid trimester, uterine incarceration is possible, but the likelihood of this complication is low. Pathophysiology Normal pelvic anatomy permits the fundus of the uterus to move relatively freely in the sagittal, vertical, oblique, and anteroposterior planes. In retroversion, the uterus is tipped posteriorly and may be fixed in this position by the presence of adhesions. Cases of marked retroversion with the uterine fundus positioned below the sacral promontory in the hollow of the pelvis lead to incarceration as the uterus enlarges during pregnancy. As the uterus becomes bigger, the fundus progressively moves posteriorly as it cannot escape from the cul de sac. As this occurs, the cervix is driven underneath and then behind the pubic symphysis. At some critical juncture of uterine size, tissue laxity, and other unknown factors, the uterus becomes entrapped. At this point, the fundus cannot easily exit the hollow of the sacrum or it is incapable of spontaneously rotating anteriorly past the sacral promontory.
As gestation advances, the incarceration worsens. Because the enlarging uterus cannot rotate anteriorly, it is wedged progressively firmly into the hollow of sacrum while the cervix exerts increasing pressure toward the urethra and/or bladder. Normal voiding eventually becomes difficult or impossible as progressive upward cervical pressure restricts normal funneling of the bladder outlet and obliterates the posterior uterovesical angle. Clinical Presentation Recurrence is possible. Thus, women with a history of symptomatic incarceration should be evaluated frequently in the late first trimester and early second trimester to ensure that the uterus does not become fully incarcerated if it remains retroverted.
Diagnosis The diagnosis of incarceration is established by performing a pelvic examination and pelvic sonography and by considering these data in combination with the characteristic clinical history.
Treatment Possible therapies for retroversion with incarceration include the following:
Bladder decompression and patient positioning The best initial treatment for symptomatic mid trimester incarceration of a normal uterus is a trial of bladder decompression combined with a program of patient positioning. Such management relieves most cases. Manipulation of the uterus Before the procedure begins, the woman is instructed to void, or, if a Foley catheter was placed, it is fully drained. An attendant is present to support and encourage the patient and to help prevent a fall. In the replacement procedure, a speculum is passed and the anterior lip of the cervix is grasped by using a long Allis clamp or another atraumatic clamp. The patient is then placed in the knee-chest or all-fours position. The surgeon inserts a finger into the vagina or rectum and applies pressure to the incarcerated fundus while simultaneously applying gentle but constant traction to the cervix. With this combined technique, the uterus should slowly rotate into its normal position. In theory, passing the fundus to either side of the sacral promontory, where more room is available, is probably best. Use of real-time sonographic guidance during manipulation procedures is prudent. Successful replacement is verified by means of palpation and real-time ultrasonography. Postprocedural care After any procedures to attempt uterine replacement, administration of Rh immunoglobulin is indicated in Rh-negative patients who are not isoimmunized. Etiology of retroversion In non pregnant women, if retroversion alone is the cause of symptoms, these are usually minimal. Pelvic pain and similar symptoms are principally due to coincidental pathology. Evidence to show that isolated retroversion is responsible for abortion or infertility is lacking. When these conditions are encountered, another etiology must be sought. Multiple gestations Multiple gestations, which now often occur in association with assisted reproductive technologies, are special cases. In this setting, the uterus can become incarcerated earlier in gestation than when only a single fetus is present. This change is presumably due simply to the increased size of the uterus. Therefore, if characteristic symptoms occur in women with known multiple gestations—even when the pregnancy has not reached 12 weeks of gestation—retroversion or incarceration should remain in the differential diagnosis. Persistent retroversion In a few cases, the uterus remains retroverted and cannot be repositioned despite the administration of tocolysis and the use of regional anesthesia. The best management strategy in this setting is moot. Patients should be informed that both symptomatic incarceration and efforts for its relief carry some risk of pregnancy loss. Ultrasonography Because of the general uncertainties, a real-time sonographic examination should precede any intervention. This imaging study is done to reassure both the patient and practitioner, to verify the original diagnosis, to confirm that an anatomically normal and living fetus is present, and to verify that a mass or tumor is not the cause of the incarceration. The study is repeated after repositioning to confirm success of the procedure to verify the presence of an active fetus and normal amniotic fluid. Other Syndromes of Pelvic Pain/Retroversion In non pregnant patients, the evaluation of chronic pelvic pain that accompanies uterine retroversion includes a consideration of 2 indistinct and somewhat suspect syndrome complexes: pelvic congestion syndrome (PCS) and Allen-Masters syndrome (AMS). Pelvic congestion (Taylor) syndrome Another possible diagnosis is PCS, or Taylor syndrome. This condition is characterized by menometrorrhagia and symptoms of continuous pelvic pain. On examination, the uterus is variably enlarged and soft, and some degree of tenderness is present. Uterine retroversion is again a common but not invariable finding. The cervix may be patulous or cyanotic. Among other treatment possibilities, both hysterectomy and vascular embolization have been used to manage PCS. The symptoms of this condition are nonspecific and poorly defined. Both this and the AMS are suspect diagnostic entities. In unusual or difficult cases, MRI can safely complement ultrasonography to help establish the correct diagnosis. Uterine Torsion Frequency Uterine torsion is a rare condition in humans, and the existing papers are restricted to scattered case reports. Most cases of torsion are reported in the veterinary literature. Pathophysiology Dextrorotation is the most common finding. This is the normal orientation of the myometrial fibers. In rare situations, the torsion is of a sufficient degree to interfere with uterine circulation. This results in acute maternal symptoms or threatens fetal survival by directly restricting blood flow or by inducing abruption placentae.
Clinical Presentation If the torsion occurs at term, obstructed labor is possible, or an acutely abnormal electronic fetal monitoring tracing may develop. Diagnosis The clinical challenge of uterine torsion lies in its elusive diagnosis. However, MRI has recently been used to make the diagnosis prior to exploratory surgery. In general, treatment of torsion depends on the gestational age. When torsion is discovered during exploratory surgery before the period of presumed fetal survival (i.e., before 23-24 wk), promptly returning the uterus to the normal position is the principal therapy. Timing of diagnosis and maternal/fetal risk Because potentially serious sequelae are possible, establishing the correct diagnosis of uterine torsion early, before complications ensue, is the challenge for clinicians. Frequency Frequency Postpartum partial or complete uterine inversion is an uncommon but potentially life-threatening obstetric complication. Pathophysiology
Clinical Presentation Early-onset postpartum hemorrhage and the sudden appearance of a vaginal mass followed by various degrees of maternal cardiovascular collapse are the classical symptoms. Postpartum hemorrhage is usually the most striking symptom and initially commands the clinician's attention. Diagnosis The following entities are included in the differential diagnosis of uterine inversion:
Treatment Rapid diagnosis and aggressive management of uterine inversion minimizes the principal risks of acute inversion, which are hemorrhage, and cardiovascular collapse or shock. Proper treatment tests the ability of the institution to mount a prompt team-based response to this normally unanticipated, but potentially serious, obstetric complication. After uterine inversion occurs, prompt treatment of hemorrhage and shock is vital in limiting maternal morbidity and the risk of mortality. Summon nursing assistance and another surgeon.
Insert a Foley catheter. Treat aggressively Administer oxygen.
Attempt prompt replacement of the uterus:
Repair Manually replace uterus. Uterine Prolapse Frequency Uterine prolapse during gestation is an infrequent clinical problem, though moderate degrees of descensus are common before pregnancy, especially in multiparas. If not severe, pregnancy-associated prolapse often partially or completely resolves in the mid trimester as the fundus grows and the uterus becomes an abdominal organ, drawing the cervix upward. In such cases, symptomatic prolapse usually recurs in the third trimester, or, on occasion, it is first observed at this time. Pathophysiology The female pelvic viscera are best considered to be suspended from above and supported from below. To maintain the pelvic organs in their proper position, their suspensory and support structures must remain intact and interact. This joint function depends on the integrity of the muscular, fascial, and neurologic components of these various tissues. Substantial injury to one or more of these systems can result in a loss of support and result in a degree of prolapse that may prove permanent. Clinical Presentation Signs and symptoms associated with uterine prolapse may include the following:
Diagnosis Establishing the diagnosis is not a challenge. On examination, the clinician observes unusual cervical descent, accompanied by variable protrusion of the anterior and posterior vaginal walls. Treatment Aspects of treatment are as follows:
Serious complications A number of serious complications are there in association with prolapse during pregnancy. |
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