An evidence-based evaluation of endometriosis-associated infertility.

Although endometriosis is associated with infertility, a clear causal relationship has yet to be established, unless adhesive disease is found. Despite this indirect association, multiple theories have been promulgated and studies are currently underway to investigate theoretic pathogenetic mechanisms. The data regarding the treatment of endometriosis-associated infertility are limited and conflicting; however, some general preliminary conclusions can be drawn. It seems that, with early-stage disease, surgical treatment increases pregnancy rates. Using the US Preventive Services Task Force classification scheme, the evidence in support of this finding is of the highest quality, or level I. Surgical treatment for moderate and severe disease also confers benefit, although the evidence in support of this treatment is of lesser quality, level II-3 by the scheme. Medical treatment, particularly if it induces an anovulatory state, has no benefit and may delay fertility. This evidence is again of the highest quality, with a classification of level I. Although assisted reproductive technologies are of benefit regarding fertility for women with endometriosis, the IVF evidence is inconclusive, with both treatments being evaluated by at least one randomized, controlled trial conferring a level I classification to the evidence. It is unclear at this time whether endometriomas have an impact on IVF outcome. The evidence consists of only a few lower-quality studies, with a classification level of II-2. Despite the haziness of current insight into the treatment of endometriosis-associated infertility, well-designed clinical trials and basic mechanistic investigations are underway in many reproductive medicine centers. As the data from these scientific inquiries emerge, clinicians will have a clearer view of effective treatment regimens for endometriosis.