O-056 Can we tailor ART to endometriosis patients?
Authors: Mijatovic V 
Published: July 2024

Abstract
ART remains an effective treatment for endometriosis-associated infertility, although there is evidence that pregnancy rates are diminished in women with endometriosis compared with other etiologies of infertility.
In this lecture, the literature relating to endometriosis-associated infertility will be evaluated and recommendations will be made on the management of patients both pre-ART and during ART in order to improve ART outcomes in women with endometriosis.
Surgery as an adjuvant to ART appears to have a favorable effect in patients with minimal to mild endometriosis prior to IVF. However, this evidence is based on only one study and more research is needed. As deep endometriosis (DE) is usually accompanied by advanced intra-abdominal disease resulting in distortion of the pelvic anatomy and tubal dysfunction, it is not surprising that IVF is considered as first line treatment. Observational data are available on the outcomes of DE surgery regarding conception rates in infertile patients with endometriosis suggesting that surgery may increase natural pregnancy rates as well as improve IVF outcomes. However, randomized trials comparing IVF to DE surgery are non-existent, as DE surgery is still mainly performed for pain and reduced quality of life rather than for treating infertility.
In order to improve IVF success rates in endometriosis, various pre-ART treatments have been suggested. The oldest one relates to the use of gonadotropin releasing hormone (GnRH) agonist prior to IVF. Currently there is uncertainty as to whether long-term GnRH agonist therapy is beneficial when compared to standard IVF/ICSI in endometriosis. In addition, there is no evidence to support the use of oral GnRH antagonists and oral contraceptives as pre-treatment prior to ART, but results of ongoing studies will determine further.
More recent studies support defects in endometrial receptivity as a cause of IVF failure. In recent years a new marker for endometrial receptivity in endometriosis emerged: BCL6, a biomarker for endometrial inflammation as it stimulates endometrial cytokine expression. Prospective cohort data provide a proof of concept that high BCL6 expression is associated with adverse IVF outcomes in women with endometriosis and that patients with high BCL6 expression may benefit from medical and surgical treatment prior to IVF.
In order to improve IVF success rates in endometriosis, various pre-ART treatments have been suggested. The oldest one relates to the use of gonadotropin releasing hormone (GnRH) agonist prior to IVF. Contrary to previous findings, there is currently uncertainty as to whether long-term GnRH agonist therapy is beneficial when compared to standard IVF in endometriosis. In addition, there is also no evidence to support the use of oral GnRH antagonists and oral contraceptives as pre-treatment prior to ART in endometriosis, but results of ongoing studies will determine further.
It has been hypothesized that applying local endometrial injury might induce a beneficial effect on endometrial receptivity prior to ART. However, scratching the endometrium as well as infusing fluids (Lipiodol and ExEm gel) into the uterine cavity (uterine bathing) in endometriosis patients prior to ART did not improve IVF success.
During ART, a specific protocol for ART in women with endometriosis cannot be recommended. Both GnRH agonist and antagonist protocols can be used. For ovarian stimulation, a higher dose of gonadotropins may be required in stage III-IV endometriosis due to a poorer ovarian response. There is insufficient evidence for the routine use of prophylactic antibiotics at the time of oocyte retrieval in patients with endometriosis, but their use is recommended in patients with endometrioma. Considering fertilization, there appears no added benefit in using ICSI over IVF in endometriosis unless male-factor infertility is present. Finally, there is insufficient evidence to recommend any particular luteal support in women with endometriosis undergoing ART.