Adenomyosis is the ectopic location of endometrial tissue deep to the endometrial-myometrial junction. Like endometriosis, adenomyosis is defined by the ectopic location of endometrial tissue and is associated with aberrant gene expression in the eutopic endometrium.  Increasingly, the endometrio-myometrial interface is implicated as a distinct functional zone within the uterus fundamental to our understanding of reproductive uterine dysfunctions.

Like endometriosis, the diagnosis and clinical significance of adenomyosis remains enigmatic and has been implicated in menstrual disturbance, pain and infertility. Unfortunately, the association with endometriosis confounds studies of this condition.

The relationship between infertility and uterine adenomyosis and/or adenomyomata remains controversial. In humans, adenomyosis is a condition primarily associated with multiparity, not with infertility. Adenomyosis demonstrates a correlation with parity, history of uterine trauma including caesarean sections, spontaneous and induced abortions, and endometrial hyperplasia.  Fertility studies in this area are limited by diagnostic difficulties, poor study design, confounding by the association with endometriosis and lack of diagnostic criteria. Some authors have demonstrated adverse effects, while others have failed to demonstrate any difference.  Inflaming the controversy, authors have demonstrated improvements in pregnancy rates with surgical and medical therapy, further confounding the problem.

Until appropriate trials can be conducted, both the impact on fertility and the treatment of any such effect remains largely conjectural.