Endometriosis affects sperm–endosalpingeal interactions L.Reeve1, H.Lashen1 and A.A.Pacey1,2 1Academic Unit of Reproductive and Developmental Medicine, Level 4, The Jessop Wing, Royal Hallamshire Hospital,

BACKGROUND: The interaction between spermatozoa and the epithelium of the isthmic region of the uterine tube is thought to be an important part of the mechanisms of sperm transport to the site of fertilization and in pre-paring them for fertilization. However, it is unclear whether a dysfunction of this mechanism may contribute to subfertility in some individuals. METHODS: The sperm-binding characteristics of the epithelium from the uterine tubes of three groups of women were examined: (i) eight with pelvic endometriosis (not involving the uterine tubes); (ii) five women who had been receiving zoladex injections to control their symptoms; and (iii) as controls 10 women undergoing an elective procedure for benign gynaecological problems but with no other pathology of the reproductive tract. RESULTS: Significantly more spermatozoa bound per unit area to the ampullary epithelium of the uterine tubes taken from women with a previous diagnosis of endometriosis. CONCLUSIONS: These findings suggest that the characteristics of sperm binding to tubal epithelium may be disrupted in women with a gynaecological pathology such as endometriosis. It is suggested that this may have the potential to interfere with the availability of freely motile spermatozoa, of the appropriate physiological status, to take part in fertiliza-tion. This may be a newly described mechanism by which endometriosis can cause infertility. Key words: endometriosis/endosalpinx/pathology/spermatozoa