gineco ro ultrasonography Müllerian Duct Anomalies: Clinical Issues and of 3D Ultrasound Diagnosis Mihaela Grigore, MD, PhD1, Camelia Cojocaru, MD2, Alina Mareş, MD3, Anca Indrei, MD, PhD4 1. Department of Obstetrics and Gynecolgy, University of Medicine and Pharmacy Gr.T. Popa Iasi, Medis Medical Center; 2. Cuza Vodă Hospital Iași, Medis Medical Center Iasi; 3. Cuza Vodă Hospital Iași; 4. Deparment of Anatomy, University of Medicine and Pharmacy Gr.T. Popa Iaşi Correspondence: Mihaela Grigore e-mail: [email protected] Abstract The incidence of uterine malformations is esti- two-dimensional pelvic sonogram is its inabil- mated to be between 3% and 4% in the general ity to reconstruct the uterine coronal axis. The population. Their impact is noted in infertility imaging of this axis has major significance in problems such as preterm labor, intrauterine diagnosing the uterine fundus malformation. growth restriction and pathological lie or pre- In recent years further advances in ultrasonog- sentation. Until recently, the use of invasive raphy have led to three-dimensional ultraso- tests, such as laparoscopy, hysteroscopy, or nography (3DUS). hysterosalpingography, was required for di- This review shows the advantages of the three- agnosing congenital uterine anomalies. Since dimensional ultrasound as a diagnostic tool. some of this malformation can be surgically The authors also present several examples of corrected, pre-surgical pelvic imaging has both uterine malformations from their own experi- a diagnostic and a therapeutic value. ence. One of the common imaging methods is the Keywords: uterine malformations, clinical is- pelvic sonogram. A major disadvantage of sues, 3D ultrasound The incidence of uterine malforma- Embryology There are four other important facts tions is estimated to be between 3% The uterus develops from the two pa- to be kept in mind: and 4% in the general population. The ramesonephric ducts (Mullerian ducts). uterine malformations are often as- prevalence of the particular types of the The caudal two thirds of these ducts sociated with upper vaginal malfor- uterine malformations is difficult to give rise to the uterus and the upper mations because the 2/3 of the vagina assess due to the different populations third become the Fallopian tubes. The has the same embryologic origin as studied, to small sample sizes, to pros- development of the uterus is divided the uterus pective versus retrospective study into the three stages and failure or arrest uterine anomalies are often asso- designs, to different classification sys- of development during these stages ciated with urinary tract anomalies tems, and to the types of test used in explains the occurrence of uterine (kidneys, urethra) due to close em- diagnosing(1). malformations. bryological interactions; 100 Vol. 5, No. 2/may 2009 gineco ro Table 1 The development of the uterus and uterine malformations Failure Stage Normal development Uterine malformations of normal development The appearance of Müllerian ducts and their caudal 6-9 weeks → Uterine aplasia midline fusion and connection with urogenital sinus The upward fusion of the caudal parts of the Müllerian Uterine duplications- uterus 10-13 weeks → ducts didelphys, bicornuate uterus The resorption of the medial septum initially separating the caudal parts of the Müllerian ducts to form the uterine septation (septate 4-18 weeks → uterovaginal duct as the origin of both uterine cavity and uterus) superior 2/3 of the vagina the independent ovarian and Mül- 5. Septate uterus - represent partial When the serosal indentation is more lerian ducts development explains or complete nonresorption of the utero- than 1 cm, this indicates a bicornuate the generally normal ovarian mor- vaginal septum; uterus(8). The configuration of the ex- phology and function in the cases 6. Arcuate uterus - result from near ternal uterine contour is essential for of uterovaginal developmental ano- complete resorption of the septum; the differentiation of a septate from a malies; 7. DES drug related uterus - com- bicornuate uterus, because different cli- uterine malformations are usually prises sequelae of in utero DES exposure. nical and therapeutic approaches are not associated with chromosomal As observed, this classification has sim- assigned to each anomaly(9). The sur- or sexual differentiation anomalies. plified the categorization of Müllerian gical treatment for a septate uterus is anomalies. However, some uterine ano- hysteroscopic resection of the septum. Classification malies may have characteristics of one Bicornuate uteri rarely necessitate The most basic classification of Mül- or more categories. Despite its flaws, the surgical intervention, although Stras- lerian duct defects consists of agenesis AFS classification provides a basis for sman metroplasty (wedge resection of and hypoplasia, defects of vertical fu- communication and comparison between the medial aspect of each uterine horn sion, and defects of lateral fusion. In investigators. and subsequent unification of the two 1979, Buttram and Gibbons proposed cavities) may be applied in patients a classification of Müllerian duct ano- Septate Uterus with recurrent second-trimester abor- malies that was based on the degree The septate uterus is the most com- tion and premature delivery(10). It is of failure of normal development, and mon Müllerian duct anomaly. Fifty- important to recognize that mild con- they separated these anomalies into five percent of uterine anomalies are cavity of the external uterine contour classes that demonstrate similar clinical septate(4,5). This anomaly results from should not be construed as a “partial” manifestations, treatment, and prognosis partial or complete failure of resorption bicornuate configuration, because these for fetal rescue(2). This classification of the uterovaginal septum after fusion patients may not be given the option of was modified in 1988 by the American of the paramesonephric ducts. Since the hysteroscopic metroplasty. Fertility Society (now the American paramesonephric ducts have previously In general, septate uteri have the Society of Reproductive Medicine), and fused, the serosa of the uterine fundus poorest reproductive outcomes of at the moment this represent the most is intact. The septum arises in the Müllerian anomalies(6). The poor repro- used one(3). The American Fertility midline fundus and can be complete ductive outcome can be explained by Society (AFS) classified Müllerian ano- or partial. A complete septum extends several mechanisms: malies according to the major uterine to the external cervical os(6). A partial endometrial mucosa covering the anatomic types: septum is variable in length and may septum does not respond appro- 1. Hypoplasia/agenesis - segmental be mild or extend to the endocervical priately to estrogen agenesis and variable degrees of utero- canal proximal to the external os. The abnormal distribution of vessels vaginal hypoplasia; external uterine contour may be convex, within the septum 2. Unicornuate uterus - partial or flat, or mildly concave(4,7). Although the irregular contractions of muscular complete unilateral; AFS classification do not specify the fibers in the septum(8,11,12,13). 3. Didelphys uterus - duplication minimal depth of fundic indentation Salim et al have reported that the of the uterus results from complete for differentiation of a septate from a more complete the septum, the higher nonfusion of the Müllerian ducts; bicornuate or a uterus didelphys the the pregnancy failure rate(12). It has 4. Bicornuate uterus - demonstrates general consensus is that a distance of not yet been determined why some incomplete fusion of the superior seg- less than 1 cm will differentiate between patients with a septate uterus carry ments of the uterovaginal canal; the septate uterus and bicorn uterus(4). a pregnancy to term and others have Vol. 5, No. 2/may 2009 101 gineco ro ultrasonography recurrent miscarriages(11). Because it is indentation and the distance between are two hemi-uteruses and two cer- not always associated with a poor obste- the lateral apices of the horns is calcu- vices. A longitudinal and transverse trical history, the incidental finding of a lated on the basis of HSG findings, an vaginal septum may also be present uterine septum is not an indication for adverse reproductive outcome is not with subsequent hematometrocolpos. hysteroscope incision(4,11). Hysteroscopic anticipated(4). However, a defining depth There is no communication between the incision of a septum (in order to restore of the indentation to differentiate an duplicated endometrial cavities. Non- normal uterine cavity) is indicated in arcuate configuration from a broad obstructive uterus didelphys is usually women with a longstanding history of septum has not been established. asymptomatic, while uterus didelphys unexplained infertility. When evaluating with unilateral vaginal obstruction may the uterus following hysteroscopic Bicornuate Uterus become symptomatic at menarche and metroplasty, no residual septum or evi- Ten percent of uterine anomalies manifest as dysmenorrhea. Due to the dence of a residual septum measuring up are bicornuate which results from retrograde menstrual flow in patients to 1 cm in length is considered indicative incomplete fusion of the uterine horns. with obstruction, endometriosis and of optimal resection(14). Reproductive A bicornuate uterus consists of two pelvic adhesions have an increased pre- outcome has been shown to improve symmetric