Endometriosis and fertility

Endometriosis affects roughly 10% of women of reproductive age globally, which is approximately 190 million women worldwide. This makes it one of the most common conditions that affect the reproductive system.

For those with endometriosis, how it affects fertility can be a worry. 30-50% of women with endometriosis struggle to fall pregnant naturally, meaning that many individuals access fertility treatments to help them become parents.

In this guide, we explain what endometriosis is and how endometriosis and fertility are linked, before discussing different fertility treatment options.

What is endometriosis?

Endometriosis is a condition where cells similar to those located in the womb's lining grow in other places of the body, such as the ovaries or fallopian tubes.

Each month, these cells react to the changing hormone levels in the same way as the ones in the womb's lining: by breaking down and being removed as a period bleed. However, the endometriosis cells that are not in the womb's lining cannot be removed from the body as they should be and instead build up in the body. This in turn causes inflammation, pain, and the formation of scar tissue.

In the UK, 1.5 million women and those assigned female at birth are diagnosed with endometriosis. It can affect women of any age, including teenagers and women going through menopause.

Symptoms of endometriosis

The symptoms of endometriosis may vary between individuals and depend on the severity of the condition. Some women may be affected badly, whereas others are less so.

Some common symptoms of endometriosis include:

• Pain in your lower stomach or back (also called pelvic pain) – usually worse during your period

• Heavy periods

• Very strong period pain (such that stops you from doing your normal activities)

• Pain during or after sex

• Pain when urinating during your period

• Feeling sick, constipated, or having diarrhoea

• Blood in your urine during your period

• Difficulty getting pregnant

Does endometriosis affect fertility?

Natural conception is possible if you have endometriosis and it doesn’t necessarily cause infertility. However the condition can make getting pregnant harder. 

The chance of a couple of reproductive age getting pregnant each month where the woman does not have endometriosis is around 15-20%. However, where the woman has untreated endometriosis, this likelihood falls to between 2% and 10%.

Endometriosis and fertility issues

The link between endometriosis and fertility issues isn’t fully understood. However, theories have been put forward as to how endometriosis can cause infertility.

The scar tissue that severe endometriosis causes can distort the pelvic anatomy by creating adhesions. For example, if one of your ovaries is wrapped in adhesions, when an egg gets released, this may become trapped and be unable to reach the fallopian tube.

There is also research indicating that endometriosis can affect your ovarian reserve. Endometriosis causes cysts, called endometriomas, on or around the reproductive organs and these cysts occur in 17-44% of people with endometriosis. Studies have found that the egg count of women with endometriomas is decreased compared to similarly aged healthy women or women with benign ovarian cysts.

According to Endometriosis UK, in cases of minimal or mild endometriosis, infertility may be a result of:

• Toxins in peritoneal fluid (naturally occurring fluid within the body cavity)

• Problems with egg transport down the fallopian tube

• An abnormal immune response (antibodies)

• Failure of the egg sac (follicle) to release its egg (luteinised unruptured follicle syndrome)

There is also a risk that surgery used in the treatment of endometriosis can affect your fertility as it may cause damage to the uterus, fallopian tubes, and ovaries.

Endometriosis and fertility treatments

If you’re having difficulty getting pregnant, fertility treatments encompass a range of options that can improve reproductive outcomes for individuals with endometriosis.

Endometriosis and IVF

In vitro fertilisation (IVF) is a recommended fertility treatment option for many individuals with endometriosis. By stimulating the ovaries to produce multiple eggs, retrieving them, and fertilising them with sperm in a laboratory setting, IVF can bypass potential obstacles posed by endometriosis-related fertility issues such as if your fallopian tubes are blocked or heavily scarred due to the condition.

However, how endometriosis impacts IVF success rates is still unclear. Some studies suggest that women with IVF have similar cycle outcomes to those without the condition. Other research has found that the stage of endometriosis treatment influences outcomes, with women in early treatment or late treatment having higher live birth rates than untreated women with moderate to severe endometriosis.

Endometriosis and frozen embryo transfer

Frozen embryo transfer (FET) offers a promising approach for individuals with endometriosis seeking fertility treatment. FET involves thawing cryopreserved embryos from a prior embryo freezing or IVF cycle and transferring them into the uterus during a carefully timed cycle, potentially increasing the chances of successful implantation and pregnancy while minimising the impact of endometriosis.

A study published in 2019 found that in frozen-thawed cycles, pregnancy rates were similar between those with endometriosis and those without (26.2% vs. 31.6%), as well as live birth rates (22.2% vs. 26.2%).

Endometriosis and IUI

Intrauterine insemination (IUI) can be a suitable fertility treatment option for individuals with minimal or mild endometriosis, who ovulate regularly and have healthy fallopian tubes. By placing washed and concentrated sperm directly into the uterus during ovulation, IUI increasesenhances the chances of sperm reaching the fallopian tubes and fertilising an egg.

IUI can also be done with ovarian stimulation where you use medication to produce several eggs in one month as opposed to a single egg. Research has established that ovarian stimulation with IUI significantly increases pregnancy rates compared to either no treatment or IUI alone for those who have minimal or mild endometriosis. Another study found that patients undergoing IUI with ovarian hyperstimulation after laparoscopy surgery achieved higher pregnancy (53.4%) and live birth rates (48.3%) than those who did not have the fertility treatment (38.5% and 34.2% respectively).

Can you donate eggs if you have endometriosis?

The eligibility to donate eggs if you have endometriosis is dependent on a range of factors. Having endometriosis doesn’t automatically mean you cannot become an egg donor, but your age, the severity of your condition, egg reserve and egg quality all need to be considered. This is for your well-being as much as it is to ensure a positive outcome for all involved in the egg donation process.

In summary, endometriosis is a common gynaecological condition affecting approximately 10% of women, and . aAlthough natural pregnancy is possible, 30-50% of women with endometriosis struggle to fall pregnant. Fertility treatments can increase the likelihood of pregnancy, however, the recommended type of treatment is dependent on your individual circumstances, the severity of your endometriosis, its impact on your reproductive anatomy and whether you have had any treatment for the condition.

If you want to find out more about your fertility treatment options, you can book a free consultation with an Apricity Fertility Advisor. During the call, you’ll be able to ask any questions you may have, find out more about the fertility treatments we offer and our partner clinics, and even order at-home fertility tests to help you get started on your path to parenthood.

References

• https://www.who.int/news-room/fact-sheets/detail/endometriosis

  
  

• www.endometriosis-uk.org

  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538128/

  
  

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6897522/

  
  

• https://www.endometriosis-uk.org/sites/default/files/2023-02/Endometriosis%20UK%20-%20Endometriosis%2C%20Fertility%20and%20Pregnancy%20Jan%202023.pdf

  
  

• https://www.sciencedirect.com/topics/medicine-and-dentistry/endometriosis-and-infertility

• https://www.nhs.uk/conditions/endometriosis/complications/

  
  

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4512514/

  
  

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6707971/