Prevalence of adenomyosis features in women scheduled for assisted reproductive treatment, using the Morphological Uterus Sonographic Assessment group definitions.

Introduction: Studies that use standardized ultrasonographic criteria to diagnose adenomyosis in subfertile women are needed. These would improve the understanding of the disease burden and enable further studies on its impact on fertility and assisted reproductive treatment (ART) outcome. The aim of this study was to determine the prevalence of different features of adenomyosis in women scheduled for their first ART, diagnosed at two (2D) and three-dimensional (3D) transvaginal ultrasonography (TVUS) using the revised Morphological Uterus Sonographic Assessment (MUSA) group definitions.

Material And Methods: This was a prospective, observational cross-sectional study of subfertile women aged 25 to ≤39 years, that were referred to a university hospital for their first ART between December 2018 and May 2021. Of 1224 eligible women, 1160 women fulfilled the inclusion criteria and consented to participate in the study. All women underwent a systematic 2D and 3D TVUS examination. The primary outcome was the presence of direct and indirect features of adenomyosis, as proposed by the MUSA group. Secondary outcomes were to describe the ultrasonographic characteristics of the different features, as well as any difference in the diagnostics at 2D or 3D TVUS and any association with clinical characteristics such as endometriosis.

Results: At least one direct or indirect feature of adenomyosis was observed in 272 (23.4%, 95% confidence interval [CI] 21.0-25.9) women. Direct features that are pathognomonic for the disease were observed in 111 (9.6%, 95% CI, 7.9-11.3) women. Direct features were visible only at 3D TVUS in 56 (4.8%, 95% CI 3.6-6.1) women, that is, 56/111 (50.5%) of women with at least one direct adenomyosis feature. Direct features were more common in women with endometriosis (OR 2.8, 95% CI 1.8-4.3).

Conclusions: We found than one in 10 women scheduled for ART had direct features of adenomyosis at ultrasound examination. The present study suggests that the use of 3D TVUS is an important complement to 2D in the diagnostics of adenomyosis. Our results may further improve the counseling of women scheduled for ART and enables future studies on the impact of different features of adenomyosis on subfertility, ART results and obstetric outcomes.