Epidemiologic factors have been extrapolated primarily from cohorts of women with pelvic pain and infertility, which complicate the assessment of prevalence. It is generally accepted that up to 10% of reproductive-aged women are affected by endometriosis.[3]Sangi-Haghpeykar H, Poindexter AN. Epidemiology of endometriosis among parous women. Obstet Gynecol. 1995 Jun;85(6):983-92.
http://www.ncbi.nlm.nih.gov/pubmed/7770271?tool=bestpractice.com
[4]Zondervan KT, Becker CM, Missmer SA. Endometriosis. N Engl J Med. 2020 Mar 26;382(13):1244-56.
http://www.ncbi.nlm.nih.gov/pubmed/32212520?tool=bestpractice.com
[5]Fuldeore MJ, Soliman AM. Prevalence and symptomatic burden of diagnosed endometriosis in the United States: national estimates from a cross-sectional survey of 59,411 women. Gynecol Obstet Invest. 2017;82(5):453-61.
http://www.ncbi.nlm.nih.gov/pubmed/27820938?tool=bestpractice.com
Endometriosis is most commonly diagnosed between the ages of 18 and 29 years.[5]Fuldeore MJ, Soliman AM. Prevalence and symptomatic burden of diagnosed endometriosis in the United States: national estimates from a cross-sectional survey of 59,411 women. Gynecol Obstet Invest. 2017;82(5):453-61.
http://www.ncbi.nlm.nih.gov/pubmed/27820938?tool=bestpractice.com
Women with a first-degree relative with endometriosis have a 7- to 10-fold increased risk of having it themselves.[6]Falcone T, Flyckt R. Clinical management of endometriosis. Obstet Gynecol. 2018 Mar;131(3):557-71.
http://www.ncbi.nlm.nih.gov/pubmed/29420391?tool=bestpractice.com
[7]Malinak LR, Buttram VC Jr, Elias S, et al. Heritage aspects of endometriosis. II. Clinical characteristics of familial endometriosis. Am J Obstet Gynecol. 1980 Jun 1;137(3):332-7.
http://www.ncbi.nlm.nih.gov/pubmed/7377253?tool=bestpractice.com
Genetic predisposition to the disease has been well documented in sibling pair studies.[8]Simpson J, Elias S, Malinak LR, et al. Heritable aspects of endometriosis. I. Genetic studies. Am J Obstet Gynecol. 1980;137:327-31.
http://www.ncbi.nlm.nih.gov/pubmed/7377252?tool=bestpractice.com
[9]Bischoff F, Simpson JL. Genetic basis of endometriosis. Ann N Y Acad Sci. 2004 Dec;1034:284-99.
http://www.ncbi.nlm.nih.gov/pubmed/15731320?tool=bestpractice.com
Documentation of endometriosis requires a more thorough examination than may be performed during procedures with indications other than pelvic pain. A study that assessed pathologic specimens from women undergoing vaginal hysterectomy for chronic pelvic pain documented a rate of endometriosis of 8.3%.[10]Wheeler JM. Epidemiology of endometriosis-associated infertility J Reprod Med. 1989 Jan;34(1):41-6.
http://www.ncbi.nlm.nih.gov/pubmed/2704007?tool=bestpractice.com
Higher estimates may be seen in cohorts undergoing laparoscopy for pelvic pain (12% to 70%) or infertility (9% to 50%), especially in adolescent populations who have chronic pain refractory to medical management.[11]Missmer SA, Hankinson SE, Spiegelman D, et al. Reproductive history and endometriosis among premenopausal women. Obstet Gynecol. 2004 Nov;104(5 Pt 1):965-74.
http://www.ncbi.nlm.nih.gov/pubmed/15516386?tool=bestpractice.com
[12]Guo SW, Wang Y. Sources of heterogeneities in estimating the prevalence of endometriosis in infertile and previously fertile women. Fertil Steril. 2006 Dec;86(6):1584-95.
http://www.ncbi.nlm.nih.gov/pubmed/17067588?tool=bestpractice.com
[13]Laufer MR, Goitein L, Bush M, et al. Prevalence of endometriosis in adolescent girls with chronic pelvic pain not responding to conventional therapy. J Pediatr Adolesc Gynecol. 1997 Nov;10(4):199-202.
http://www.ncbi.nlm.nih.gov/pubmed/9391902?tool=bestpractice.com
Such a large range of estimates may be explained by heterogeneity in study design with more recent studies including diagnostic criteria not previously established.[12]Guo SW, Wang Y. Sources of heterogeneities in estimating the prevalence of endometriosis in infertile and previously fertile women. Fertil Steril. 2006 Dec;86(6):1584-95.
http://www.ncbi.nlm.nih.gov/pubmed/17067588?tool=bestpractice.com
Global trends of disease are even less reliable due to the reliance on surgical findings as confirmation of disease and the inconsistent documentation of pelvic pain in the literature.[14]Latthe P, Mignini L, Gray R, et al. Factors predisposing women to chronic pelvic pain: systematic review. BMJ. 2006 Apr 1;332(7544):749-55.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1420707
http://www.ncbi.nlm.nih.gov/pubmed/16484239?tool=bestpractice.com
An epidemiological assessment from the ENDO Study Working Group provided estimates of prevalence based on operative findings as well as magnetic resonance imaging, suggesting that endometriosis may be more prevalent than previously reported, with a strong association with infertility.[15]Peterson CM, Johnstone EB, Hammoud AO, et al. Risk factors associated with endometriosis: importance of study population for characterizing disease in the ENDO Study. Am J Obstet Gynecol. 2013 Jun;208(6):451;e1-11.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4114145
http://www.ncbi.nlm.nih.gov/pubmed/23454253?tool=bestpractice.com
Endometriosis typically affects women of reproductive age, but a wide spectrum of age at diagnosis exists.[4]Zondervan KT, Becker CM, Missmer SA. Endometriosis. N Engl J Med. 2020 Mar 26;382(13):1244-56.
http://www.ncbi.nlm.nih.gov/pubmed/32212520?tool=bestpractice.com
Contrary to previous paradigms, premenarcheal girls presenting with chronic pelvic pain should be evaluated for endometriosis as this condition has been reported in this young cohort.[16]Marsh EE, Laufer MR. Endometriosis in premenarcheal girls who do not have an associated obstructive anomaly. Fertil Steril. 2005 Mar;83(3):758-60.
http://www.ncbi.nlm.nih.gov/pubmed/15749511?tool=bestpractice.com
Adolescents who complain of moderate-to-severe dysmenorrhea since menarche and whose complaints progress and become more acyclic may have endometriosis. This group is often overlooked.[1]American College of Obstetricians and Gynecologists. Dysmenorrhea and endometriosis in the adolescent. ACOG committee opinion no. 760. Obstet Gynecol. 2018 Dec;132(6):e249-58 (reaffirmed 2021).
https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2018/12/dysmenorrhea-and-endometriosis-in-the-adolescent
http://www.ncbi.nlm.nih.gov/pubmed/30461694?tool=bestpractice.com
[17]European Society of Human Reproduction and Embryology Endometriosis Guideline Development Group. Guideline on the management of women with endometriosis. Feb 2022 [internet publication].
https://www.eshre.eu/Guidelines-and-Legal/Guidelines/Endometriosis-guideline.aspx
Furthermore, endometriosis can present in menopausal women.[2]Al Kadri H, Hassan S, Al-Fozan HM, et al. Hormone therapy for endometriosis and surgical menopause. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD005997.
http://www.ncbi.nlm.nih.gov/pubmed/19160262?tool=bestpractice.com
The prevalence is thought to be higher in white women and in those with a lower body mass index.[11]Missmer SA, Hankinson SE, Spiegelman D, et al. Reproductive history and endometriosis among premenopausal women. Obstet Gynecol. 2004 Nov;104(5 Pt 1):965-74.
http://www.ncbi.nlm.nih.gov/pubmed/15516386?tool=bestpractice.com
[18]Bougie O, Yap MI, Sikora L, et al. Influence of race/ethnicity on prevalence and presentation of endometriosis: a systematic review and meta-analysis. BJOG. 2019 Aug;126(9):1104-15.
http://www.ncbi.nlm.nih.gov/pubmed/30908874?tool=bestpractice.com