Endometriosis and infertility
The mechanisms by which endometriosis may cause infertility are not clearly understood, particularly when the extent of endometriosis is low. Still possible mechanisms include:
- Anatomical distortions and adhesions (the fibrous bands that form between tissues and organs following recovery from an injury)
- The release of factors from endometriotic cysts which are detrimental to gametes or embryos. An endometriotic cyst contains free iron, reactive oxygen species, proteolytic enzymes and inflammatory molecules. Follicular density in tissue surrounding the endometriotic cyst has been consistently shown to be significantly lower than in healthy ovaries, and to a degree that does not appear to be caused merely by the stretching of surrounding tissues owing to the presence of a cyst.
The other way around, endometriosis may more likely develop in women who fail to conceive for other reasons and thus be a secondary phenomenon. For this reason it is preferable to speak of "endometriosis-associated infertility" rather than any definite "infertility caused by endometriosis" by the same reason that association does not imply causation.
Surgery is more effective for infertility than hormonal suppression for endometriosis. Surgery enhances the chances of conceiving naturally during the 12-18 ensuing months. The use of medical suppression after surgery for minimal/mild endometriosis has not shown benefits for patients with infertility.
The use of fertility medication that stimulates ovulation (clomiphene citrate, gonadotropins) combined with intrauterine insemination (IUI) enhances fertility in these patients as does assisted reproduction.
In vitro fertilization
In-vitro fertilization (IVF) procedures are effective in improving fertility in many women with endometriosis. IVF makes it possible to combine sperm and eggs in a laboratory and then place the resulting embryos into the woman's uterus. The decision when to apply IVF in endometriosis-associated infertility cases takes into account the age of the patient, the severity of the endometriosis, the presence of other infertility factors, and the results and duration of past treatments. In ovarian hyperstimulation as part of IVF in women with endometriosis, using a standard GnRH agonist protocol has been found to be equally effective in regard to using a GnRH antagonist protocol in terms of pregnancy rate. On the other hand, when using a GnRH agonist protocol, long-term (three to six months) pituitary down-regulation before IVF for women with endometriosis has been estimated to increase the odds of clinical pregnancy by fourfold.
No difference has been found between surgery (cystectomy or aspiration) versus expectant management, or between ablation versus cystectomy, prior to IVF in women with endometriosis.
- Endometriosis and infertility: a committee opinion, from American Society for Reproductive Medicine. Revised 2012
- Buyalos RP, Agarwal SK (October 2000). "Endometriosis-associated infertility". Current Opinion in Obstetrics and Gynecology. 12 (5): 377–81. doi:10.1097/00001703-200010000-00006. PMID 11111879.
- Speroff L, Glass RH, Kase NG (1999). Clinical Gynecologic Endocrinology and Infertility (6th ed.). Lippincott Willimas Wilkins. p. 1057. ISBN 978-0-683-30379-7.
- Sanchez, A. M.; Vigano, P.; Somigliana, E.; Panina-Bordignon, P.; Vercellini, P.; Candiani, M. (2013). "The distinguishing cellular and molecular features of the endometriotic ovarian cyst: from pathophysiology to the potential endometrioma-mediated damage to the ovary". Human Reproduction Update. 20 (2): 217–230. doi:10.1093/humupd/dmt053. ISSN 1355-4786. PMID 24129684.
- Moen MH (November 1991). "Is a long period without childbirth a risk factor for developing endometriosis?". Hum Reprod. 6 (10): 1404–7. doi:10.1093/oxfordjournals.humrep.a137278. PMID 1770135.
- "ACOG Committee Opinion No. 760: Dysmenorrhea and Endometriosis in the Adolescent". Obstet Gynecol. 132 (6): e249–e258. December 2018. doi:10.1097/AOG.0000000000002978. PMID 30461694.
- de Ziegler D, Pirtea P, Carbonnel M, Poulain M, Cicinelli E, Bulletti C, Kostaras K, Kontopoulos G, Keefe D, Ayoubi JM (February 2019). "Assisted reproduction in endometriosis". Best Pract Res Clin Endocrinol Metab. 33 (1): 47–59. doi:10.1016/j.beem.2018.10.001. PMID 30503728.
- Wellbery, Caroline (15 October 1999). "Diagnosis and Treatment of Endometriosis". American Family Physician. 60 (6): 1753–1762. PMID 10537390. Retrieved 19 August 2013.
- Farquhar, Cindy; Marjoribanks, Jane (17 August 2018). "Assisted reproductive technology: an overview of Cochrane Reviews". The Cochrane Database of Systematic Reviews. 8: CD010537. doi:10.1002/14651858.CD010537.pub5. ISSN 1469-493X. PMC 6953328. PMID 30117155.