How common is adenomyosis? A prospective study of prevalence using transvaginal ultrasound in a gynaecology clinic

Abstract

What is the prevalence of adenomyosis in a population of women attending a general gynaecological clinic? Adenomyosis was present in 206 of 985 [20.9%; 95% confidence interval (CI): 18.5-23.6%] women included in the study. Previous studies of occurrence of adenomyosis have been limited to women who underwent hysterectomy, which is likely to overestimate its prevalence compared with the general population of women. There are no large prospective studies on the prevalence of adenomyosis, either in the general population of women or in a general gynaecology clinic setting. This was a prospective observational study set in the general gynaecology clinic of a university teaching hospital between January 2009 and January 2010. There were 985 consecutive women who attended the clinic and underwent structured clinical and transvaginal ultrasound examination in accordance with the study protocol. Morphological features of adenomyosis were systematically recorded with the ultrasound scan to determine its prevalence and factors which may affect its occurrence. Adenomyosis was present in 206/985 [20.9% (95% CI: 18.5-23.6%)] women included in the study. Multivariate analysis showed that the prevalence of adenomyosis was significantly associated with women's age, gravidity and pelvic endometriosis (P< 0.001). In women who subsequently underwent hysterectomy, there was a good level of agreement between the ultrasound and histological diagnosis of adenomyosis [κ = 0.62 (P = 0.001), 95% CI (0.324, 0.912)]. Our estimate of prevalence of adenomyosis is likely to be higher than in the general population as we studied symptomatic women attending a gynaecology clinic. Better estimates of the prevalence of adenomyosis can improve our understanding of the burden of the disease, help to identify women at high risk of developing the condition and facilitate the development of preventative strategies and effective treatment. The authors have no competing interests to declare. The study was not supported by an external grant.