Endometriosis and assisted reproductive technologies.

The association between endometriosis and infertility is well established, and different mechanisms have been postulated to cause infertility depending on the stage of endometriosis. Controlled ovarian hyperstimulation improves pregnancy outcome for minimal to mild endometriosis; however, there are no randomized controlled studies of this technique in patients with severe disease. Further, ART appears to have an overall beneficial effect for all stages of endometriosis. Based on the current staging system, several studies have not been able to demonstrate a significant difference in true outcomes for different stages of the disease. The limitations of these studies have been discussed above. Similarly, the effect of endometriomas when considered independent of the stage is still unclear. In addition to ART, pretreatment with GnRH analogues or surgical intervention may be beneficial and needs to be addressed in randomized controlled studies. It is evident that we urgently need large randomized studies to answer several questions about the treatment of endometriosis-associated infertility with ART. Although our current practice is based primarily on retrospective observational studies and small randomized studies, the overall impact on pregnancy outcome is beneficial.