Adenomyosis is a condition in which the glandular part of the lining of the uterus (the endometrium) grows more deeply than usual and is seen in the muscular wall. It is difficult to diagnose adenomyosis from a scan and it is highly unlikely that it is relevant to anything as long as endometriosis is not present as well. Most uteruses seem to develop some degree of adenomyosis as time goes by and most women get pregnant without any trouble. Severe adenomyosis is usually blamed for heavy or painful periods but not for subfertility.