Clinical characteristics of different subtypes of adenomyosis in infertility

This study aimed to compare the clinical histories and clinicopathological characteristics between internal and external adenomyosis (ADM) among infertile women. A total of 759 infertile patients aged 24 to 40 years were enrolled from the Sports New City Branch of Dalian Maternal and Child Health Hospital (Group) from June 2018 to September 2024. All patients were divided into 3 groups according to magnetic resonance imaging-based ADM typing: internal ADM group (n = 418), external ADM group (n = 113), and non-ADM control group (n = 228). Baseline clinical histories and clinicopathological parameters were statistically compared among the 3 groups. Significant differences in clinical historical features were identified among different ADM subtypes. A history of intrauterine surgery was verified as an independent risk factor for internal ADM, while endometriosis was an independent risk factor for external ADM. Subtype-specific disparities were also observed in clinicopathological profiles. Endometritis was an independent clinicopathological feature of internal ADM, whereas posterior myometrial thickening, elevated serum carbohydrate antigen 125 levels, and decreased anti-müllerian hormone levels were independent clinicopathological characteristics of external ADM. Internal and external ADM subtypes present distinct clinical histories and clinicopathological features, indicating fundamental phenotypic differences between the 2 subtypes in infertile populations.