The more than expected prevalence of endometriosis in patients with Mullerian abnormalities

The more than expected prevalence of endometriosis in patients with Mullerian abnormalities

Both obstructive and non-nonobstructive malformations in the lower genital tract are often associated with endometriosis.

Key Points


  • The togetherness of endometriosis and uterine malformations has been always a tricky condition that should be kept in mind while managing patients with either disease.


  • There is an increased prevalence of endometriosis in women with uterine malformations indicating the importance of adding a hysteroscopy procedure to endometriosis surgery.

What's done here:

  • The patient data of an academic hospital, from Germany between 2014 to 2019 were analyzed retrospectively.
  • The patients who were diagnosed with uterine malformations were selected and who had both laparoscopy and hysteroscopy were included in the study (n=279).
  • The uterine malformations were classified with the American Fertility Society classification system.

Key Results:

  • Out of 279 cases analyzed, 94.2 % had non-obstructive, 4.3 % had an obstructive uterine malformation, and the remaining 1.4 % had uterine agenesis/hypoplasia.
  • From patients with uterine malformations, 74.9 % had histologically confirmed endometriosis, 25.1 % did not.


  • Although the authors made a presumption about the possible mechanism causing this coexistence no preclinical arm was added to the study to enlighten the reason.
  • The results should be confirmed with mechanical investigations and molecular studies.

Lay Summary

Congenital müllerian anomalies resulting in a spectrum of uterine abnormalities are caused by the abnormal embryologic fusion of the müllerian ducts to form a normal uterine cavity.  They are often unrecognized because they are usually asymptomatic. The presence of a uterine anomaly increases the risk of pregnancy loss and adverse pregnancy outcomes. The classification of uterine anomalies by American Fertility Society classification includes hypoplasia/agenesis, unicornuate, didelphys, bicornuate, septate, arcuate, and diethylstilbestrol-related.

The prevalence of uterine malformations is up to 38 percent in patients with habitual pregnancy loss and up to 5 percent in the all-female population. 

Uterine malformations and endometriosis have a high chance to be together and it is possibly due to the increased retrograde menstruation, according to authors.

The present study conducted by Piriyev et al., as a retrospective data analysis from Academic Hospital, Cologne, Germany, investigated the coexistence of uterine malformations and endometriosis. The data were analyzed according to the American Fertility Society classification and rASRM classification systems. The main results published recently in the "Archives of Gynecology Obstetrics", showed a higher presence of endometriosis in patients with Mullerian abnormalities comparing to the literature (74.9 percent to 56.8 percent).

The patients with non-obstructive malformations in the lower genital tract did also have endometriosis, which was explained by the authors with impaired uterine peristalsis caused by any Mullerian abnormality.

The authors concluded that it should be kept in mind that patients with uterine malformations might have endometriosis and who has a previous diagnosis with endometriosis should also have a uterine evaluation preferably with hysteroscopy.


Research Source:

uterine malformations Müllerian abnormalities endometriosis pregnancy loss agenesis unicornuate didelphys septate arcuate adverse pregnancy outcome


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