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It affects two million women in the UK so if you’re suffering, you’re definitely not alone. Here’s all the information you need

What is endometriosis?

Endometriosis is a long-term condition. It’s where tissue that’s similar to the inner lining of the womb (endometrium) grows outside of the womb. This tissue might grow in places like the bowel, bladder, ovaries, fallopian tubes or the lining of the abdomen (UCLH, 2018).

Is that why endometriosis is often linked to infertility?

Yes. The problems caused by endometriosis, particularly in women who have moderate and severe cases, can make it difficult for them to get pregnant (Endometriosis UK, 2008).  

How is endometriosis diagnosed?

It can be as simple as talking through your symptoms, period history and mentioning any pain during or after sex. If it is still unclear whether you have it, endometriosis can be diagnosed with a pelvic examination, an ultrasound scan or a laparoscopy (a tube with a tiny camera) (NHS Choices, 2015; UCLH, 2018).

If someone has endometriosis, will they be able to get pregnant?

Probably. Most women with endometriosis will get pregnant in the end, without treatment (NHS Choices, 2015). It depends how severe your symptoms are (Rossi and Prefumo, 2016).  

What are the signs and symptoms of endometriosis?

The misplaced tissue will continue to behave like the endometrial tissue in your womb and bleed during your period. This may cause severe period pain as well as bleeding between periods, inflammation, cysts and scarring. It can also cause pain in the lower abdomen, pelvis or lower back, and pain during and after sex (NHS Inform, 2018).

Other endometriosis symptoms can include persistent exhaustion and tiredness, discomfort going to the toilet and bleeding from the back passage or blood in your poo (NHS Inform, 2018).

How common is it?

Endometriosis affects around 8% to 10% of women in their reproductive years (Eskenazi and Warner, 1997). That is around two million women in the UK.

What causes endometriosis?

This is a tricky one. The exact cause is still unknown but a few factors are probably at play. For most women, some of the inner lining of the womb flows backwards during their period through the fallopian tubes and into the abdomen. But while the body normally clears these tissues, for women with endometriosis the tissue attaches to the pelvic or abdominal organs or the abdominal wall (Endometriosis UK, 2008).

Why does that happen to some women and not others?

Possibly because of a weaker immune system (Jerman and Hey-Cunningham, 2015). Genetics – family history of endometriosis – may also play a role (Kennedy et al, 1995; Simpson and Bischoff, 2002; Stefansson et al, 2002). Environmental factors like toxins that affect the immune and reproductive system may also be involved (Louis et al, 2013; Porpora et al, 2013).

Other potential causes are metaplasia, which is where one type of cell changes into another to adapt to its environment. Some research suggests that in women with endometriosis, certain abdominal cells mistakenly turn into endometrial cells (Healthy Women, 2018).

Lymphatic spread may be another factor (Jerman and Hey-Cunningham, 2015). This is where tiny bits of endometriosis tissue travel around the body through the lymphatic system.

What’s the treatment for endometriosis?

The pain is managed with painkillers like ibuprofen and paracetamol (NHS Choices, 2018b). The most common way to treat endometriosis itself is with hormones like gonadotrophin releasing hormone analogues (GnRH)  and contraceptives like the pill (NHS Choices, 2015).  They work by limiting or stopping the production of oestrogen that encourages the growth of endometrial tissue (UCLH, 2018). They can also stop periods, easing symptoms.

But what if I’m trying to conceive?

Right now, there is no suitable treatment for managing endometriosis while trying to conceive if the condition is making it difficult for you to get pregnant. Opinions are mixed over whether surgery to remove the endometrial tissue and ease endometriosis symptoms could also help with trying to conceive (Marcoux et al, 1997; NHS, 2015; Nickkho-Amiry et al, 2018; Tommy’s, 2018).

Is there anything else that can help someone with endometriosis conceive?

Several types of fertility treatments are available for women with endometriosis who are having trouble conceiving. They include IVF, intrauterine insemination (IUI), ovarian stimulation with IUI and gamete intrafallopian tube transfer (GIFT) (Endometriosis UK, 2008).

That’s a lot of medical terms

Don’t worry, specialists can advise on which treatment is best depending on your particular situation.

If pregnancy happens, will endometriosis affect it?

Pregnancy should be no different from normal, although some studies have found that endometriosis may increase the risk of premature birth and miscarriage. It may also raise the risk of a few other pregnancy-related complications (NHS Choices, 2009; Tommy’s, 2018).

The pregnancy itself may actually alleviate your endometriosis symptoms. But they are likely to return after the baby is born.

Is there anywhere people can go for support?

Yes, absolutely. Try Endometriosis UK and speak to your GP if you are experiencing anxiety or depression due to endometriosis.

This page was last reviewed in February 2018.

Further information

Our support line offers practical and emotional support with feeding your baby and general enquiries for parents, members and volunteers: 0300 330 0700.

We also offer antenatal courses which are a great way to find out more about birth, labour and life with a new baby.

NHS choices provides information on the diagnosis and treatment of the condition and its effect on fertility.

Endometriosis UK aims to improve the lives of people affected by endometriosis and work towards a future where it has the least possible impact on those living with endometriosis.

Bischoff F, Simpson JL. (2004) Genetic basis of endometriosis. Annals of the New York Academy of Sciences. 1034:(284-299). Available from: https://www.ncbi.nlm.nih.gov/pubmed/15731320 [Accessed 1st February 2018].

Endometriosis UK. (2008) Endometriosis, fertility, and pregnancy. Available from: https://www.endometriosis-uk.org/sites/default/files/files/Information/… [Accessed 1st February 2018].

Eskenazi B, Warner ML. (1997) Epidemiology of endometriosis. Obstetrics and Gynecology Clinics 24:235-258. Available from: https://www.ncbi.nlm.nih.gov/pubmed/9163765 [Accessed 1st February 2018].

Healthy Women. (2018) Endometriosis. Available from: http://www.healthywomen.org/condition/endometriosis [Accessed 1st February 2018].

Jerman LF,  Hey-Cunningham AJ. (2015) The role of the lymphatic system in endometriosis: a comprehensive review of the literature. Biology of reproduction. 92(3):64. Available from: https://www.ncbi.nlm.nih.gov/pubmed/25588508 [Accessed 1st February 2018]

Kennedy S, Mardon H, Barlow D. (1995). Familial endometriosis. Journal of assisted reproduction and genetics. 12(1):32-34. Available from: https://www.ncbi.nlm.nih.gov/pubmed/7580007 [Accessed 1st February 2018]

Louis GMB, Peterson CM, Chen Z, Croughan M, Sundaram R, Stanford J, Sun L. (2013) Bisphenol A and phthalates and endometriosis: the endometriosis: natural history, diagnosis and outcomes study. Fertility and sterility. 100(1):162-169. Available from: https://www.ncbi.nlm.nih.gov/pubmed/23579005 [Accessed 1st February 2018]

Marcoux S, Maheux R, Bérubé S; Canadian Collaborative Group on Endometriosis. (1997). Laparoscopic surgery in infertile women with minimal or mild endometriosis. New England Journal of Medicine. 337(4):217-22. Available from: https://www.nejm.org/doi/10.1056/NEJM199707243370401 [Accessed 1st February 2018]

NHS Choices. (2009) Endometriosis and birth problems. Available from:  https://www.nhs.uk/news/pregnancy-and-child/endometriosis-and-birth-problems/ [Accessed 1st February 2018].

NHS Choices. (2015) Endometriosis. Available from: https://www.nhs.uk/conditions/endometriosis/ [Accessed 1st February 2018].

NHS Inform. (2018) Endometriosis. Available from: https://www.nhsinform.scot/illnesses-and-conditions/sexual-and-reproductive/endometriosis  [Accessed 1st February 2018].

Nickkho-Amiry M, Savant R, Majumder K, Edi-O’sagie , Akhtar M. (2018) The effect of surgical management of endometrioma on the IVF/ICSI outcomes when compared with no treatment? A systematic review and meta-analysis. Archives of gynecology and obstetrics. 297(4):1043-1057. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5849664/ [Accessed 1st February 2018].

Porpora MG, Resta S, Fuggeta E, Storelli P, Megiorni F, Manganaro, De Felip E. (2013) Role of environmental organochlorinated pollutants in the development of endometriosis. Clin Exp Obstet Gynecol. 40(4):565-567. Available from: https://www.ncbi.nlm.nih.gov/pubmed/24597257 [Accessed 1st February 2018]

Rossi AC, Prefumo F. (2016) The effects of surgery for endometriosis on pregnancy outcomes following in vitro fertilization and embryo transfer: a systematic review and meta-analysis. Archives of gynecology and obstetrics. 294(3):647-55.  Available from: https://www.ncbi.nlm.nih.gov/pubmed/27300002 [Accessed 1st February 2018]

Stefansson H, Geirsson RT, Steinthorsdottir V, Jonsson H, Manolescu A, Kong A, et al. (2002) Genetic factors contribute to the risk of developing endometriosis. Human reproduction 17(3):555-559. Available from: https://www.ncbi.nlm.nih.gov/pubmed/11870102 [Accessed 1st February 2018].

Tommy’s. (2018) Endometriosis and getting pregnant. Available from: https://www.tommys.org/pregnancy-information/getting-pregnant/endometriosis-and-getting-pregnant [Accessed 1st February 2018].

UCLH. (2018) General information about endometriosis. Available from: https://www.uclh.nhs.uk/OURSERVICES/SERVICEA-Z/WH/GYNAE/ENDOM/Pages/Generalinformationabout.aspx [Accessed 1st February 2018].

Further reading

Albertsen HM, Chettier R, Farrington P, Ward K. (2013) Genome-wide association study link novel loci to endometriosis. PloS one. 8(3):e58257. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3589333/ [Accessed 1st February 2018].

Di W, Guo SW. (2007) The search for genetic variants predisposing women to endometriosis. Current Opinion in Obstetrics and Gynecology. 19(4):395-401. Available from: https://www.ncbi.nlm.nih.gov/pubmed/17625425 [Accessed 1st February 2018].

Endometriosis UK (2018). Endometriosis, fertility and pregnancy. Available from: https://www.endometriosis-uk.org/endometriosis-fertility-and-pregnancy [Accessed 1st February 2018].

Macer ML, Taylor HS. (2012) Endometriosis and infertility: a review of the pathogenesis and treatment of endometriosis-associated infertility. Obstetrics and Gynecology Clinics. 39(4):535-549. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538128/ [Accessed 1st February 2018].

Painter JN1, Anderson CA, Nyholt DR, Macgregor S, Lin J, Lee SH, et al. (2011). Genome-wide association study identifies a locus at 7p15. 2 associated with endometriosis. Nature genetics. 43(1):51-54. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3019124/ [Accessed 1st February 2018].

Uno S, Zembutsu H, Hirasawa A, Takahashi A, Kubo M, Akahane T, et al. (2010). A genome-wide association study identifies genetic variants in the CDKN2BAS locus associated with endometriosis in Japanese. Nature genetics. 42(8):707-710. Available from: https://www.ncbi.nlm.nih.gov/pubmed/20601957 [Accessed 1st February 2018].

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