Endometriosis and Fertility – What do you need to know?

Whether you have endometriosis, have a partner with endometriosis or even are just curious, you may be wondering, does endometriosis affect fertility? 

We have broken down the science below to help you answer the most frequently asked questions when it comes to endometriosis and fertility.

Is it possible to get pregnant with endometriosis?

Although it is possible to get pregnant with endometriosis, there is a chance you may experience difficulty getting pregnant and having endometriosis may also affect your pregnancy. Women with endometriosis are at an increased risk of miscarriage, ectopic pregnancy and other obstetric complications compared to those without endometriosis (Saraswat et al., 2017).

Will endometriosis affect my fertility? Will endometriosis stop me from getting pregnant?

One of the symptoms associated with endometriosis is difficulty getting pregnant or not being able to get pregnant at all. Between 30-50% of women with endometriosis experience fertility problems, and up to 50% of infertile women have endometriosis (ASRM, 2016; Zondervan et al., 2018). According to the American Society of Reproductive Medicine (ASRM), women with endometriosis have a lower chance of getting pregnant with each monthly cycle compared to women without endometriosis (2-10% vs 15-20%) (The Practice Committee of the American Society for Reproductive Medicine, 2012). 

However, having endometriosis does not automatically mean you will have problems with your fertility.

So, how might endometriosis cause infertility?

Unfortunately, in a similar way to how the cause of endometriosis is unknown, the exact cause of endometriosis-related fertility problems is unknown and will vary between individuals depending on medical history and type of endometriosis. However, there are several thoughts as to why women with endometriosis may experience a decreased chance of getting pregnant with each cycle and a longer time to pregnancy (Zondervan et al., 2018). 

One of the ways endometriosis is likely to affect fertility is by distorting the position of organs such as your uterus and Fallopian tubes. Deposits of endometrial-like cells and the subsequent formation of adhesions around the uterus and Fallopian tubes might prevent the mature egg from reaching the uterus to be fertilised. 

In the more advanced stages of endometriosis, women are at an increased risk of having blockages of their Fallopian tubes, again preventing ovulation and, therefore, fertilisation. 

The presence of cysts on your ovaries (endometriomas) could also affect fertility and ovulation by damaging the ovarian tissue and the precious ovarian follicles which house the immature eggs. 

However, this is not the whole picture, as some women with mild and moderate endometriosis and limited deposits also may experience infertility. 

Another theory about how endometriosis affects fertility is an immune reaction to endometrial-like tissue outside the uterus. As this tissue is recognised as ‘foreign’ to these parts of our body, our immune system responds by attacking it, leading to inflammation. This inflammation leads to the presence of harmful toxins in the liquid surrounding your reproductive organs (the peritoneal fluid). Some suggest this may affect both the Fallopian tube function, sperm function and egg quality, making it more difficult to get pregnant (Sanchez et al., 2017). 

There is also debate about whether endometriosis affects the receptivity of the womb to the fertilised egg. Although, again, there is currently no conclusive evidence to prove this theory. 

Painful sex is one of the symptoms associated with endometriosis. Pain during or after intercourse can negatively impact your sex life and make the trying-to-conceive process difficult.

Does treating endometriosis increase fertility?

A woman experiencing significant pelvic pain and other symptoms of endometriosis will be offered diagnostic laparoscopy and subsequent laparoscopic surgery to remove the endometrial-like deposits and adhesions. This procedure aims to increase potential fertility by freeing the pelvic organs, reducing inflammation and removing endometrial deposits. 

If you have an endometrioma, you may be offered something called a laparoscopic ovarian cystectomy, i.e. the removal of the endometriosis-related cysts on the ovaries (European Society of Human Reproduction and Embryology, 2022). This surgery has been shown to lower the recurrence rate of both cysts and pain symptoms. 

However, it is really important to remember that opting for surgery is a big decision, one which must be discussed between yourself and your doctor. You will have a discussion with your doctor about the risks and benefits of surgery for you personally. For example, although ovarian cystectomy is able to improve spontaneous pregnancy rate in some cases, it also may negatively affect your ovarian reserve through the removal of healthy tissue. 

Trying to conceive with endometriosis 

Women experiencing difficulty getting pregnant who have suspected endometriosis will receive a general fertility check-up according to ESHRE and ASRM guidelines (European Society of Human Reproduction and Embryology, 2022). The treatment options available for women with endometriosis-related infertility will rely on your age, your partner’s age, the location and severity of your endometriosis and the results of infertility investigations that have been conducted on yourself and your partner. 

So, what fertility treatments are available if you are trying to conceive with endometriosis?

Treatment options for women trying to conceive include expectant management, medications, surgery, or assisted reproductive techniques (ARTs). 

Expectant management (i.e. trying to conceive naturally) is a viable option for young women with suspected endometriosis who have a normal ovarian reserve, normal Fallopian tube function, are not experiencing pelvic pain, have no evidence of any hormone imbalances and no issues with their partner’s fertility. 

To improve your chances of conceiving with every menstrual cycle, it is recommended to have sex every 2-3 days so there is a good chance of catching your fertile window.  Your fertile window is made up of 5-6 days in each menstrual cycle and made up of the day an egg is released from the ovary as well as the 5 days beforehand where sperm can survive in the reproductive tract. Depending on your age, ART is recommended if conception has not occurred after 6 to 12 months of trying.

Examples of ART options available to treat infertility in people with endometriosis, include Intrauterine insemination (IUI), controlled ovarian stimulation (COS) and in-vitro fertilisation (IVF). 

Although some studies have shown an increase in pregnancy rates, NICE guidelines do not recommend IUI treatments for women with endometriosis at any stage. In fact, evidence from  a recent study showed  that the chance of pregnancy was higher for the first cycle of IVF compared to 6 cycles of IUI (ETIC Endometriosis Treatment Italian Club, 2019). 

IVF is currently one of the most successful treatments which can be offered to women with moderate/severe endometriosis. Furthermore, in those with a very low egg reserve, it can help decrease the time to conception. IVF is known to be less successful in people with endometriosis compared to those without endometriosis . However, many other factors influence IVF success, such as your age, whether or not you have had a previous pregnancy and body mass index. 
As part of your IVF cycle, you may be offered something called Intracytoplasmic sperm injection or ICSI for short. Instead of simply mixing your partner/donor’s sperm, in ICSI, an individual sperm is selected and injected into the egg. This treatment is usually used to overcome male factor infertility, however it is also provided for those who are using frozen eggs or want to conduct genetic testing on their embryos.  There is currently no evidence to suggest ICSI improves live birth rates in women with endometriosis compared to a regular IVF cycle (Tan et al., 2018).

Should I have endometriosis surgery before undergoing ART? 

Opting for surgery before undergoing any form of fertility treatment or ART is up to the discretion of you and your clinician. Specialist guidelines (ASRM and ESHRE) advise against surgery before ART as there is no conclusive evidence that it improves ART outcomes. For women with deep endometriosis, surgery may improve pregnancy outcomes however the evidence is limited. 

If you are experiencing any symptoms indicative of endometriosis or want to understand where your fertility and reproductive health is currently at, we’re here to get you the answers you deserve. The Hertility Health journey includes a tailored at-home hormone test, fertility & gynaecology triage service, digital personalised results, access to highly-rated experts and clinics, educational content and a community of care. We’re here to support you throughout your reproductive journey, from menstruation to menopause.