Septate Uterus

A uterine septum is the most common of all müllerian anomalies, accounting for just over half of all abnormalities, and it is the most common structural uterine anomaly. After the 2 müllerian ducts fuse in the midline, resorption must occur to unify the endometrial cavities; failure of this process results in some degree of uterine septum. It can vary in length from just below the fundus to beyond the cervix, depending on the amount of caudal resorption. A septate uterus has a normal external uterine contour, which is what distinguishes it from a bicornuate or didelphic uterus. An MRI can help delineate between a predominantly fibrous septum and a muscular or myometrial septum. Because the septum may be poorly vascularized, a septate uterus is the most significant anomaly associated with pregnancy loss, as well as other untoward pregnancy outcomes. Hysteroscopic metroplasty (septal excision) is generally recommended in the setting of a previous pregnancy loss. Controversy still exists regarding whether a woman should have such a surgical procedure without a previous pregnancy loss. The length of the septum might not correlate with the frequency or occurrence of untoward pregnancy outcomes. Differentiating precisely between bicornuate and septate uteri is extremely important to determine effective and safe treatment plans.

Bicornuate Uterus

Both müllerian ducts develop and elongate in this anomaly, but they do not completely fuse in the midline. The vagina and external cervix are normal, but the extent of division of the two endometrial cavities can vary depending on the extent of failed fusion between the cervix and the fundus. Bicornuate uteri are also associated with increased preterm labor and delivery, malpresentation, and miscarriage. This anomaly accounts for about 10-20% of müllerian anomalies and a significant percentage of uterine anomalies.

Unicornuate Uterus and Rudimentary Horns

A unicornuate uterus results from a normal creation of a fallopian tube, functional uterus, cervix and vagina from one müllerian duct. The other side fails to develop, resulting in either absence of the contralateral müllerian duct or a rudimentary horn. There is a 30-40% association of renal anomalies. If a rudimentary horn is identified, it is important to determine whether functional endometrium is present (usually with T2-weighted MRI images). About of rudimentary horns are noncommunicating, some with a fibrous band connecting the 2 structures. Rudimentary horns can also communicate with the contralateral uterus. A fertilized ovum can implant and develop within a rudimentary horn. These pregnancies are incompatible with expectant gestation, and rupture of the horn could be life threatening. Rupture tends to occur at a later gestation than with an ectopic pregnancy, and hemorrhage is severe. Patients with rudimentary horns with functioning endometrium can also present with pain due to accumulating menses. Because the other horn has a normal outflow pathway, these patients present with pain, not primary amenorrhea. Pregnancies that arise in a unicornuate uterus are associated with increased preterm labor and delivery, malpresentation, and miscarriage.

Uterine Didelphys

A uterine didelphys is the result a complete failure of fusion and represents 5% of müllerian anomalies. There are 2 fallopian tubes, 2 completely separate uterine cavities, 2 cervices, and often 2 vaginal canals or 2 partial canals because of an associated longitudinal vaginal septum (75% of the time). Evaluation for renal anomalies should be pursued because they are common as well. At times, the longitudinal septum attaches to 1 sidewall and obstructs 1 side of the vagina (or hemivagina). The combination of uterine didelphys, obstructed hemivagina, and ipsilateral renal agenesis is a variant of the broad spectrum of müllerian anomalies that is referred to as the Heryln-Werner-Wunderlich syndrome (HWWS) or obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome in the literature (Fig. 548-1). Adolescents with this disorder usually present with abdominal pain shortly after menarche. Although there still may be a risk of adverse pregnancy outcomes with a uterine didelphys (preterm labor, malpresentation), overall pregnancy outcomes are generally good and are associated with less risk than in other uterine anomalies.

Figure 548-1 Occluded right hemivagina and absent right kidney. A, A 2 day old girl presented with a gray cystic mass at the vaginal introitus. B, Intravenous urography shows no right renal function (probably absent kidney). In a cystogram (not shown), the bladder was displaced forward by the mass. The patent left hemivagina could be catheterized and was found to be markedly displaced to the left. On frontal (C) and lateral (D) vaginograms, contrast material introduced through a needle inserted in the cystic mass at the introitus opacifies a markedly distended right hemivagina and uterus (unilateral hydrometrocolpos) (asterisks). Contrast material from previous studies is still present in the patent vagina (V) and bladder (b).

(From Slovis TL, editor: Caffey’s pediatric diagnostic imaging, ed 11, Philadelphia, 2008, Mosby, p 2438.)

Arcuate Uterus

An arcuate uterus is a uterine cavity that has a small midline septum, from lack of a small amount of resorption, and sometimes a slight indentation of the uterine fundus. An arcuate uterus might represent a variant of normal rather than a müllerian anomaly. Untoward pregnancy outcomes are rare and surgical correction is not warranted.

Uterine Anomalies in DES-Exposed Patients

Intrauterine diethylstilbestrol (DES) exposure is associated with an increased risk for development of uterine anomalies and clear cell adenocarcinoma of the vagina and cervix. DES was used to prevent preterm delivery, and this practice was discontinued in 1971. Commonly observed uterine features associated with DES exposure include a T-shaped uterus, cervical hypoplasia, fallopian tube irregularities, scalloped or irregularly shaped endometrial contour, constriction bands, and others. DES has been shown by several researchers to suppress and/or alter Wnt and HOX genes in mice, and thus might work by affecting gene expression in müllerian duct development, causing uterine abnormalities, vaginal adenosis, and potentially carcinoma.

Treatment

Treatment depends on the specific anomaly. Hysteroscopic surgical resection is widely supported for uterine septa. If a septate uterus extends through the cervical canal, many choose to leave this cervical portion of the septum due to concerns for future incompetence, although incisions have been done with uneventful follow-up in case reports. Most would support the incision of a uterine septum in the clinical setting of pregnancy loss, but some would also support prophylactic metroplasty without a history of miscarriage, especially before in vitro fertilization.

A noncommunicating horn with functional endometrium should be resected to improve quality of life or prevent future complications; opinions vary as to whether resection of a communicating horn or one with no functional endometrium is warranted. Any surgical resection of a rudimentary horn requires careful surgical technique to protect the ipsilateral ovarian blood supply and the myometrium of the remaining unicornuate uterus.

Although metroplasty had been advocated with didelphic and bicornuate uteri and a history of poor pregnancy outcomes in the past, currently most clinicians feel there is not enough evidence to support such a complicated procedure. Any obstruction to the outflow tract must also be relieved; this can necessitate creation of a vaginal window or excision of a hemivaginal septum.

Abnormalities of the Hymen

An imperforate hymen is the most common obstructive anomaly, and familial occurrences have been reported. Its incidence is most often reported as approximately 1:1,000. In the newborn period and early infancy, it may be diagnosed by a bulging membrane due to a mucocolpos from maternal estrogen stimulation of the vaginal mucosa. This can eventually reabsorb if it is not too large or symptomatic. More often it is diagnosed at the time of menarche, when menstrual fluid accumulates. The clinical manifestations often are a bulging blue-black membrane, pain, primary amenorrhea, and normal secondary sex characters. Depending on the circumstance, patients might have cyclic abdominal pain or a pelvic mass. Other hymenal abnormalities have been reported. A normal hymen can have various configurations (annular, crescentic). Some hymenal membranes do not undergo complete resorption or perforation, resulting in microperforate, cribiform, or septate shaped hymen. Infants and children vary in age as to when these are recognized, but hymenal anomalies are often discovered after menarche when it is difficult for an adolescent to place a tampon

Congenital Absence of the Vagina and Mayer-Rokitansky-Küster-Hauser Syndrome

Vaginal agenesis or atresia results when the vaginal plate fails to canalize. On physical exam it appears as an extremely foreshortened vagina, sometimes referred to as a vaginal dimple. Isolated (partial) vaginal agenesis involves an area of aplasia between the distal vaginal portion and a normal upper vagina, cervix, and uterus. On initial presentation it may be confused with a low transverse septum or imperforate hymen, and therefore clear delineation of the anomaly is critical before attempting surgical repair. It can also manifest with cyclic pain and a bulging mass just after menarche. Surgical repair and reconstruction are complicated and individualized and best performed with consultation of specialists.

Uterine and vaginal agenesis often occur together because of their close association during development, when müllerian ductal development fails early in the process. The most common cause of vaginal agenesis is Mayer-Rokitansky-Kuster-Hauser syndrome (MRKH), with an incidence reported at 1:4,000-10,000 female births. The cause is unknown and likely has a multigenetic and multifactorial etiology. MRKH is characterized by primary amenorrhea, normal vulva, anomalies of the uterus (usually aplasia or agenesis), attenuated fallopian tubes, normal ovaries, normal female karyotype and phenotype, and associated anomalies (most commonly renal and skeletal). The vagina either is completely absent or only has a small dimpled opening. MRI imaging is often necessary to determine if any small uterine remnant is present (often located on the pelvic sidewall or near the ovaries and only a small fibromuscular remnant) and to clearly delineate the anomaly. Absence of the vagina and uterus has significant anatomic, physiologic, and psychologic implications for the patient and family. Any diagnosis of müllerian agenesis must be differentiated from androgen insensitivity (testicular feminization) as well; karyotype, serum testosterone levels, and pubic hair distribution usually help distinguish the two.

Lesions involving other organ systems occur in association with the Mayer-Rokitansky-Küster-Hauser syndrome. The most common are urinary tract anomalies (15-40%) primarily involving unilateral absence of a kidney, a horseshoe or pelvic kidney, and skeletal anomalies (5-10%), which primarily involve vertebral development.

Longitudinal Vaginal Septa

Longitudinal vaginal septa represent failure of complete canalization of the vagina. These often occur in the presence of uterine anomalies as noted earlier.

Transverse Vaginal Septa (Vertical Fusion Defects)

Vertical fusion defects can result in a transverse septum, which may be imperforate and associated with hematocolpos or hematometra in adolescents or with mucocolpos in infants. These are much less common anomalies, reportedly found in 1:80,000 females. Most patients present with amenorrhea and cyclical pain around the time of menarche. Patients who have a small opening in the transverse septa might present with prolonged vaginal drainage and discharge. Transverse vaginal septa vary in location in the vagina (15-20% in the lower third, but most in the middle or upper third of the vagina) and thickness, but are generally ≤1 cm thick. High locations, thick septa, and narrow vaginal orifices present challenging surgical cases.

Transverse vaginal septa may be associated with other congenital anomalies, although this occurs less often than with müllerian agenesis. These patients have a functional normal uterus, unlike women with MRKH. There is also an increased incidence of endometriosis secondary to retrograde menstruation.

Evaluation of transverse vaginal septa includes careful pelvic examination and often pelvic imaging, usually with MRI and ultrasound, to delineate the anatomic abnormalities. MRI is especially helpful to determine the thickness of the septum and presence of a cervix and for surgical planning. Diagnosis and treatment plans should be made as soon as possible after menarche, because significant accumulation of hematometria and/or hematosalpinx could affect future reproductive success by negatively affecting uterine and/or tubal function.

Treatment

An imperforate hymen requires resection to prevent or relieve the outflow tract obstruction. Many approach it with a horizontal or cruciate incision, excision of excess tissue, and reanastomosis of the mucosal edges. Repair should be done at time of diagnosis, if the patient is symptomatic. Although the lesion may be repaired any time during infancy, childhood, or adolescence, surgery is facilitated by estrogen stimulation and thus is ideally performed in adolescence, either after puberty or menarche.

Treatment of congenital absence of the vagina is usually delayed until the patient is ready to be sexually active. The nonsurgical approach is the most common first-line therapy due to the high success rate and extremely low morbidity. It requires dedicated use of dilators to create a functional vagina. The series of dilators come in progressively increasing sizes and require a commitment and maturity on the part of the patient to comply with daily use (20-30 min daily). If done correctly it is possible to achieve a functional vaginal length (6-8 cm), width, and physiologic angle for intercourse in about 6-8 wk of therapy. When the ultimate size that accommodates coitus is reached, then the patient must use the dilator or have coitus with a frequency that maintains adequate length.

Surgical approaches require more expertise and often some postoperative vaginal dilation to ensure a functional result. Controversy exists among surgical subspecialties, because pediatric surgeons and pediatric urologists often recommend creating the neovagina in infancy. Pediatric gynecologists and reproductive endocrinologists believe better outcomes result from creating the neovagina when the young woman is interested in sexual activity and can participate in the decision to have surgery and in her own postoperative recovery. There is no consensus as to the best surgical option; the most-used procedures include 2 surgical approaches followed by dilators or an approach using a loop of bowel out of which to construct a vagina. Patients need to be counseled about the ability to use their own oocytes and a gestational carrier through IVF to achieve pregnancy. These therapies can be quite complicated physically and emotionally. They are best approached in a multidisciplinary fashion, often with the assistance of psychologic counseling and surgeons with specialized training.

For transverse vaginal septa, treatment is surgical resection of the obstruction through a vaginal approach. Some surgeons advocate waiting ≥1 menstrual cycles or using preoperative dilators from below to increase the depth and circumference of the distal vagina and to allow menstrual blood to accumulate and dilate the upper portion of the vagina. Complete resection of the septum, with primary anastomosis of the upper and lower mucosal segments, should be attempted. A vaginal stent is sometimes placed postoperatively in the vagina to maintain patency and allow squamous epithelization of the upper vagina and cervix. Follow-up dilation may be necessary after the stent is removed. Careful preoperative assessment is important because surgeons who begin a case believing they are operating on an imperforate hymen can find themselves in entirely different and more complex surgical planes. Regardless of the approach, vaginoplasty is often best deferred until the patient is mature and physically and psychologically prepared to participate in the healing process and postoperative dilator treatments.

Longitudinal vaginal septa themselves do not lead to adverse reproductive outcomes but may be symptomatic in a patient, causing dyspareunia, difficulties with tampon insertion, or impedance during vaginal birth. Such complaints can warrant a resection of the vaginal septa. In a small number of patients there may be unilateral obstruction of a hemivagina, which would require incision and resection.

Complete Vulvar Duplication

Duplication of the vulva is a rare congenital anomaly that is seen in infancy and consists of 2 vulvas, 2 vaginas, and 2 bladders, a didelphic uterus, a single rectum and anus, and 2 renal systems.

Labial Asymmetry and Hypertrophy

With the onset of puberty the labia minora enlarge and grow to an adult size. A woman’s labia can vary in size and shape. Asymmetry of the labia, where the right and left labia are different in size and appearance, is a normal variant. Some women are uncomfortable with what they perceive to be their asymmetric or enlarged labia minora and complain about self-consciousness and discomfort while wearing tight clothing, exercising, or having sex. The enlarged labia can have a protuberant and abnormal appearance that can be functionally or psychologically bothersome. Local irritation, problems of personal hygiene with bowel movements or menses, interference with sexual intercourse or while sitting or exercising have resulted in requests for labial reduction. Some surgeons are advertising procedures to reduce uneven or enlarged labia minora. The American College of Obstetricians and Gynecologists does not support performing such surgery unless there is significant impairment in function. Medically indicated surgical procedures can include reversal or repair of female genital cutting and treatment for labial hypertrophy or asymmetrical labial growth secondary to congenital conditions, chronic irritation, or excessive androgenic hormones. Complications of labial surgery include loss of sensation, keloid formation, and dyspareunia.

Clitoral Abnormalities

Agenesis of the clitoris is rare. Clitoral duplication has been reported, often associated with pelvic organ abnormalities, including agenesis of other genital tract structures and bladder exstrophy.

Cloacal Anomalies

Cloacal anomalies are rare lesions representing a common urogenital sinus into which the gastrointestinal, urinary, and vaginal canals all exit. Usually there is an abnormality in all or some of the processes of fusion of the müllerian ducts, development of the sinovaginal bulbs, or development of the vaginal plate. The single opening (cloaca) requires surgical correction, preferably by a multidisciplinary pediatric surgical team.

Ductal Remnants

Even though the opposite duct regresses in both sexes, there can sometimes be a small portion of either the müllerian or wolffian duct that remains in either the male or female, respectively. Such remnants can form cysts, which is what makes them clinically visible during surgery, examination, or imaging. Most do not cause pain, although torsion of some has been reported, and small asymptomatic ones usually do not require resection. The most commonly reported are hydatid of Morgagni cysts (remnant of a wolffian duct arising from the fallopian tube), cysts of the broad ligament, and Gartner’s duct cysts, which can form an ectopic ureter or be found along the cervix or vaginal walls.