Association between endometriosis and congenital uterine malformations: A single-center retrospective study.

Study objective: The association between endometriosis and congenital uterine anomalies (CUAs) has been discussed for decades, but existing evidence about this association is scarce. The aim of our study is to evaluate the prevalence of CUAs in women with endometriosis and to identify specific characteristics in women with both CUAs and endometriosis in a large cohort of patients.

Design: This is a retrospective single-center observational study conducted between January 2006 and June 2021.

Setting: Swiss tertiary hospital PATIENTS: Women with histologically confirmed endometriosis at laparoscopy.

Interventions: All women included in this study underwent a preoperative 2D ultrasound by an experienced sonographer. In cases of suspected intrauterine pathology, bleeding disorders, or infertility, an additional hysteroscopy was performed.

Measurements and main results: Out of 1566 women with histologically confirmed endometriosis, 93 were diagnosed with CUAs (5.9%). The most frequent malformations were U1c (arcuate uterus) (41/93, 44.1%), U2a (partial septate uterus) (19/93, 20.4%), U3b (complete bicorporeal uterus) (17/93, 18.3%) and U3a (partial bicorporeal uterus) (10/93, 10.8%). Women with both CUAs and endometriosis were more frequently diagnosed with endometriosis rASRM stage IV (p=0.017) and presence of dysmenorrhea (p=0.019) in comparison to women with endometriosis and a morphologically normal uterus.

Conclusions: To the best of our knowledge, this is the largest endometriosis population examined for the prevalence of CUAs. According to our findings, the prevalence of CUAs in women with endometriosis does not appear to be higher than in the general population. However, women with CUAs and endometriosis are more likely to suffer from severe endometriosis (rASRM stage IV) and dysmenorrhea compared to endometriosis patients without CUA.