ASRM müllerian anomalies classification 2021

An updated classification system for mullerian anomalies is presented, based on the 1988 American Fertility Society classification and expanded in scope and function.

VOLUME 116, ISSUE 5, P1238-1252


Samantha M. Pfeifer, M.D., Marjan Attaran, M.D., Jessica Goldstein, R.N., Steven R. Lindheim, M.D., M.M.M., John C. Petrozza, M.D., Beth W. Rackow, M.D., Evan Siegelman, M.D., Robert Troiano, M.D., Thomas Winter, M.D., Andrea Zuckerman, M.D., Sarah D. Ramaiah, M.S.Ed.


There are many proposed classification systems for müllerian anomalies. The American Fertility Society (AFS) Classification from 1988 has been the most recognized and utilized. The advantages of this iconic classification include its simplicity, recognizability, and correlation with clinical pregnancy outcomes. However, the AFS classification has been criticized for its focus primarily on uterine anomalies, with exclusion of those of the vagina and cervix, its lack of clear diagnostic criteria, and its inability to classify complex aberrations. Despite this classification and others, the wide range of müllerian anomalies is still largely unknown and confusing to many providers. Consequently, müllerian anomalies may go undiagnosed for extended periods, receive inappropriate or inadequate surgical interventions, and result in persistent issues such as pain or loss of reproductive function. The American Society for Reproductive Medicine Task Force on Müllerian Anomalies Classification was formed and charged with designing a new classification. The Task Force set goals for a new classification and chose to base it on the iconic AFS classification from 1988 because of its simplicity and recognizability, while expanding and updating it to include all categories of anomalies. In addition, this was recognized as an opportunity to raise awareness of this area of medicine, educate providers and learners, and promote patient advocacy. Presented here is the new American Society for Reproductive Medicine Müllerian Anomalies Classification 2021.


Go to the profile of Pedro Acien
6 months ago

Comment for F&S-Dialog: https://

Pfeifer SM, Attaran M, Goldstein J, et al. ASRM müllerian anomalies classification 2021. Fertil Steril 2021;116/5:1238-1252.

Dear authors, we are surprised to read the new ASRM classification-2021 (1) and find out that it does not consider the concepts that we currently know on the genitourinary embryology and focuses only on morphological abnormalities, or imaging, of the Müllerian ducts, forgetting that in the embryonary development of the male and female genitourinary tract participates the entire urogenital ridge, the urogenital sinus and the Gubernaculum (2-4). We therefore presented an embryological and clinical classification system for malformations of the female genital tract (2-6) including 6 groups: 1) agenesis or hypoplasia of an entire urogenital ridge, 2) mesonephric anomalies, 3) müllerian anomalies, 4) Gubernaculum dysfunctions, 5) anomalies of the urogenital sinus, and 6) malformative combinations. In group 3 (isolated Müllerian anomalies) we included the AFS classification separating between anomalies of the paramesonephric or Müllerian ducts, the Müllerian anomalies tubercle, and the anomalies of both Müllerian tubercle and ducts (6).

The ASRM classification presented here might be useful for specialist in Diagnostic Imaging to dictate their Ultrasound, CT or MRI reports, but it does not seem suitable for the general clinician (including pediatricians, gynecologists and urologists) or for experts in Reproductive Medicine. In our opinion the image should induce an etiological and pathogenic diagnosis of the observed anomaly and also suggest possible associated anomalies.

The importance of embryology is such because unilateral renal agenesis (URA) is systematically associated with an ipsilateral genital abnormality in men and in women. Indeed, a distal anomaly of the mesonephric or Wolffian duct results in a triad of renal agenesis or hypoplasia (with eventual ectopic ureter in the blind vagina), uterine malformation (didelphys uterus, bicornuate, or less frequently, septate uterus) and ipsilateral blind or atretic hemivagina in women; whereas in men, it manifests by renal agenesis, seminal vesicle cyst and ejaculatory duct obstruction (Zinner syndrome), with eventual infertility (7).

And thus, considering the female genito-urinary embryology, we would say that:

The 5 images presented of Unicornuate Uterus can be associated with (right) renal agenesis: the first one clearly corresponds to patients with agenesis of all derivatives of the urogenital ridge on one side and there will usually also be extragenital (vertebral) anomalies; in 2, 3 and 4 there might be (right) renal agenesis if the uterine remnant, cavitated or not, is separated from the unicornuate uterus, and there could also be cases of mesonephric anomaly with unilateral (ipsilateral) cervico-vaginal agenesis; and number 5 is a communicating bicornuate uterus that also suggests right cervico-vaginal atresia. The same occurs in the Bicornuate Uterus number 2.

Of course, all anomalies with obstructed R/L hemivagina are mesonephric anomalies and have ipsilateral renal agenesis (or hypoplasia with eventual ectopic ureter), but there may also be partial resorption of the intervaginal septum and in that case the septum may be present only in the vaginal fundus and does not reach the lower third of the vagina.

In Complex Anomalies: number 1 would be a case of a Müllerian anomaly presenting a bicornuate uterus with bilateral cervical atresia and a normal simple vagina, which we believe is an unlikely situation being its possible etiology perhaps a segmental atresia. Number 2 is a case of communicating didelphys uterus with left cervico-vaginal atresia and as such

mesonephric anomaly, with renal agenesis (left). The figure number 3 we are not sure that the scheme is well presented but it may correspond to a mesonephric anomaly with a Gartner duct pseudocyst in the upper anterolateral wall of the vagina (as in Herlyn – Werner syndrome); number 4, according to the drawing, is an association of mesonephric anomaly with communicating bicornuate uterus (and cervico-vaginal atresia with right renal agenesis) and transverse vaginal septum or segmentary atresia (Müllerian tubercle anomaly). Number 5 is an isolated Müllerian (cervical) segmentary atresia.

So this pretended to be müllerian anomalies classification includes wolffian anomalies without acknowledging and does not mention or consider other malformations of the female genital tract such as urogenital sinus anomalies (congenital vesico-vaginal fistula and other cloacal anomalies), or the dysfunctions of the female Gubernaculum (as cavitated accessory uterine masses).

And in our opinion knowledge of the correct genitourinary embryology is essential for the understanding, study, diagnosis and subsequent treatment of genital malformations, especially complex ones and those that lead to gynecological and reproductive problems, particularly in young patients (8).

Pedro Acién, M.D., Ph.D., Emeritus Professor UMH. Department of Gynecology, Miguel Hernandez University of Elche, San Juan Campus, Alicante, Spain.

Maribel Acién, MD, PhD. Chief of Gynecology Section, San Juan University Hospital. Associate Professor. Department of Gynecology, Miguel Hernandez University of Elche, San Juan Campus, Alicante, Spain.


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