Human Reproduction vol.3 no.4 pp.459-461, 1988 Effect of endometriosis on early embryonic development in the rabbit

The reasons for sub-fertility in patients with mild endo-metriosis remain unclear. Peritoneal fluid constituents may alter tubal transport and embryonic cleavage, with subsequent implantation disturbances. We used an animal model to study the influence of endometrial implants on early embryonic development. In 25 rabbits, endometrium from the right uter-ine born was transplanted onto the peritoneum (Experimental group = Group E). In 25 rabbits, fat was transplanted (con-trol group = Group C). After a recovery period of 12 weeks the does were mated, and killed 24 h later. In the experimen-tal group the implants had changed into cysts of 5-15 mm in diameter. Histologkal examination revealed endometrial glands and stroma in every specimen. Periadnexal adhesions did not develop in any animal. No marked differences were found between Groups E and C in embryonic cleavage stage, 24 h after mating. Additional culturing of the embryos for 48 h in a suitable culture medium revealed normal further development of the embryos. Bearing in mind the restrictions of extrapolating a rabbit model to the human, it is suggested that the decreased fecundity in mild endometriosis is not caused by altered early embryonic cleavage rate. The results of this study offer indirect evidence for implantation disturb-ances as a cause of endometriosis-associated sub-fertility. Key words: embryonic development/endometriosis/rabbit