We know that endometriosis is associated with infertility and, in patients with deep infiltrating endometriosis (DIE), spontaneous pregnancy rate (without the use of assisted reproduction technologies) is estimated to be around 2 and 10% (1). Although these patients often end up using assisted reproduction in order to get pregnant, can surgical management of endometriosis increase the chances of conception?

  Let us begin by investigating the effect of endometriosis on fertility. It is estimated that around 50% of women with infertility have endometriosis (2). This is, possibly, secondary to a combination of mechanisms, mainly distortion of the normal pelvic anatomy caused by adhesions due to endometriosis, as well as the inflammatory micro-environment that do not favour fertility. What is more, endometriosis can have a negative impact on the ovarian reserve, the endometrium (the thin line that covers the inside of the womb) as well as causing painful sex (dyspareunia) that, undoubtedly, reduces the frequency of sexual intercourses. Finally, we know that endometriosis, often, coexists with adenomyosis and this co-existence has a negative impact on fertility (3).

  In order to analyse the data regarding the role of surgery, we need to remember that all cases of endometriosis are not the same! As regards the milder stages (Stage I and II according to ASRM), the European Society of Human Reproduction and Endocrinology (ESHRE) acknowledges that laparoscopic management improves spontaneous pregnancy rates (4). A well-designed, randomised trial confirmed that laparoscopic management of minimal to mild endometriosis is associated with an increase in the spontaneous conception rate (5). The same can be said about cases of unexplained infertility (6).

  As regards ovarian endometrioma (chocolate cyst of the ovary, OMA), surgical management (which usually consists of surgical excision of the cyst wall, albeit other techniques can be used) may increase the chances of spontaneous conception, however, no data from randomised studies exist (7-9). The main concern of the surgical removal of the cyst wall is the inadvertent damage/ removal of healthy ovarian tissue which can be demonstrated by the post-operative drop in the levels of anti-mullerian hormone (AMH) levels. However, it appears that, eventually, AMH levels recover to the pre-operative levels after surgery (10). Alternatively, assisted reproduction techniques can be used, with the exception of very large chocolate cysts, where access to follicles is hampered by the large size of the cyst. The surgical management of endometrioma as an adjunct before assisted reproduction is not recommended by ESHRE, since it is not clear that it improves the end result and , as mentioned previously, it causes, undoubtedly, some degree of damage to the ovary (4).

  As regards Deep Infiltrating Endometriosis (DIE) and chances of spontaneous conception, ESHRE states the surgery is an option for symptomatic women(pain). A meta-analysis found that the surgical management of women with stage III and IV endometriosis increased the spontaneous pregnancy rates from 4% to 43% (11). We can accept that surgery seems a reasonable option in case of symptomatic women, however, things are less clear in patient with DIE and infertility who are pain-free. Together with other factors that need to be taken into account (eg. Age of the patient, co-existence of other causes of infertility), surgery offers the chance to calculate the Endometriosis Fertility Index (EFI). A meta-analysis demonstrated that EFI can predict with good accuracy the chances of spontaneous conception (12). The EFI can, therefore, be used as a ‘’triage tool’’: patients with a high score can try for natural conception and those with lower score can be recommended to see a specialist in assisted reproduction. However, it needs to be remembered that DIE surgery required a high-degree of skill and may be associated with complications, something that needs to be discussed in-depth with the patient pre-operatively (13). A recent study examining the role of DIE surgery in infertility management found that, out of 1548 women, 814 of those (52.6%) were successful in achieving a pregnancy (14). Surgery also appears to have a role in cases of repeated IVF failures in patients with DIE (15): In a retrospective study of 29 patients with 1 to 5 failed IVF cycles, 22 were successful in achieving a pregnancy, of which, 15 were IVF and 7 were spontaneous.

  In conclusion, management of infertility in the context of endometriosis is complex and should be individualised. Other than endometriosis, other factors need to be taken into account, such as the age of the patient, her preferences, previous treatments, ovarian reserve and tubal patency as well factors related to her partner.Surgery has a role in cases of infertility with peritoneal endometriosis and infertility with endometrioma as it may increase the chances of spontaneous conception. In cases of infertility and DIE, surgery has a role, particularly in symptomatic patients with pain.

References

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