How does endometriosis cause infertility?

It is estimated that 50 percent of women with subfertility have the medical condition endometriosis, which typically causes heavy and painful periods. Endometriosis can block the fallopian tubes and may also have implications for IVF treatment if it affects the function of, or access to, the ovaries. To help patients with this condition, Bourn Hall has established a specialist Endometriosis Fertility Service to provide tailored advice.

Why does endometriosis cause painful periods?

During the menstrual cycle, the body prepares for pregnancy by releasing hormones that thicken the endometrial tissue that lines the womb. If the egg is not fertilised, the tissue breaks down and is released from the body as a period.

Endometriosis occurs when this endometrial tissue starts to grow in other places, attaching separate structures or organs together. During a period, this tissue swells and releases blood which is unable to leave the body, causing inflammation, pain, and the formation of scar tissue.

The symptoms can vary and may be controlled by hormonal medication such as the contraceptive pill. This means that many women are often not aware that their heavy and painful periods are not normal until they get investigated for infertility.

Shreeya Tewary discusses how endometriosis cause infertility
Bourn Hall IVF consultant Dr Shreeya Tewary has brought her expertise in endometriosis and reproductive medicine to Bourn Hall's new tailored Endometriosis Clinic

How does endometriosis cause infertility?

Endometriosis can affect fertility when the tissue creates scarring and adhesions in the pelvis. This may block the fallopian tubes or create anatomical changes that interfere with implantation of the embryo and ongoing pregnancy.

In some cases, cysts filled with blood, called endometriomas (or ‘chocolate cysts’) can form in the ovaries. These can affect the function of the ovary and the response and feasibility of IVF treatment.

Fertility investigations for those with endometriosis

Initial investigations may include a discussion of your medical history and symptoms, an AMH blood test to provide an indication of the ovarian reserve, an ultrasound scan to look at the womb and ovaries, and potentially a HyCoSy to check that your fallopian tubes are patent/open.

The fertility consultant will discuss the results of the tests and your aims, which may include improving chances of pregnancy through IUI or IVF, or fertility preservation for the future.

The presence of large endometriomas may mean that a surgical procedure is recommended to optimise fertility treatment. A further transvaginal ultrasound by the fertility specialist can assess if the ovaries are accessible and the feasibility of IVF treatment.

Following this discussion you will be given an individualised treatment plan.

Coordinating care between fertility and endometriosis specialists

If it is recommended, surgery to optimise the success of fertility treatment is available through referral to a BSGE (The British Society for Gynaecological Endoscopy) accredited Endometriosis Centre.

This can be accessed either via a GP referral to an NHS centre or directly to Cambridge EndoCare, with which Bourn Hall collaborates; this creates an integrated pathway that streamlines the coordination of care between specialists.

Where there is severe endometriosis and immediate fertility treatment is not appropriate, the eggs can be harvested and frozen at Bourn Hall ahead of excision surgery. This would increase the chances of a successful pregnancy in the future.

More information

Contact us to talk about how we can help improve your chances of pregnancy.

Find out more about Bourn Hall’s Endometriosis Clinic.

There is a special section in our Fertility Blog about endometriosis with advice for fertility specialists and patient stories.

Bourn Hall launches new Endometriosis Fertility Clinic

The European Society of Human Reproduction and Embryology (ESHRE) issued guidelines for diagnosis and treatment of endometriosis – we explain the impacts for fertility.

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