Developed in collaboration with Professor Mathilde Bourdon, France.

Being diagnosed with endometriosis can raise a lot of questions. For many people, the most immediate concern is coping with pelvic pain, heavy periods, sexual dysfunction, fatigue and other symptoms that can make everyday life incredibly difficult.

Endometriosis is a common, long-term condition that affects around 1 in 10 women. It can have a significant impact on physical health, emotional wellbeing, work, education, and relationships.

Beyond managing these often debilitating symptoms, many people also wonder what endometriosis could mean for their fertility. Approximately 30–50% of women with endometriosis have difficulty becoming pregnant, and around 25–50% of women who experience infertility also have endometriosis.

Having endometriosis does not automatically mean you won't be able to have children. Many people with the condition conceive naturally or thanks to fertility treatment. Understanding how endometriosis may affect fertility can help you make informed decisions about family planning and explore your options early if needed.

What is endometriosis?

Endometriosis is a condition where tissue that lines the interior of the uterus (endometrium) grows outside the uterus to form the endometriosis lesions (growths). These lesions are commonly found on the ovaries and the lining of the pelvis, but they can occur in other areas too like the digestive tube and urinary tracts.

Endometriosis can cause a range of symptoms, including:

• Severe period pain
• Chronic pelvic pain
• Heavy menstrual bleeding
• Pain during or after sex
• Pain when using the toilet
• Fatigue
• Difficulty becoming pregnant

Symptoms vary considerably from person to person, and some women are asymptomatic.

Getting a diagnosis can be a long and frustrating process. Because symptoms overlap with other conditions, many people wait years before receiving a diagnosis. If you think you may have endometriosis, it's important to speak to your GP or a gynaecologist who can investigate your symptoms and discuss appropriate treatment.

How can endometriosis affect fertility?

Scientists are still working to fully understand exactly how endometriosis affects fertility, and it's likely that several different factors are involved.

These may include:

• Inflammation. Endometriosis causes inflammation within the pelvis, which may affect egg quality, fertilisation, or the ability of an embryo to implant successfully. The inflammatory environment can also produce chemicals and immune cells that may reduce sperm function, making fertilisation more difficult.
• Scar tissue and adhesions. Endometriosis can lead to scar tissue and adhesions (bands of scar tissue that can make organs stick together), that change the position or function of the ovaries, fallopian tubes, or uterus, making it harder for the egg and sperm to meet.
• Reduced ovarian reserve. In some people, particularly those with ovarian endometriomas (sometimes called ovarian cysts associated with endometriosis), the number of remaining eggs in the ovaries may be reduced, especially following surgery to remove endometriomas.
• Sexual dysfunction. Endometriosis can cause significant pain during or after sexual intercourse, which can lead to a reduced sex drive or difficulties with intimacy, reducing the opportunities to conceive.

It's important to remember that endometriosis affects everyone differently. While some people experience fertility problems, many others go on to have healthy pregnancies, either naturally or with support.

What are your options if you want to have children?

If you have endometriosis and would like children now or in the future, there are several possible options. The most appropriate approach depends on factors such as your age, ovarian reserve, the severity of your endometriosis, whether there are other factors that may affect your fertility, and your family-planning goals.

Your options may include:

• Starting your journey: You can start by trying to conceive naturally. However, it is recommended you speak to a fertility specialist if you have been trying for 12 months without success (or 6 months if you're 35 or older).
• Preserving future options: If you're not ready to have children yet, fertility preservation methods like egg freezing can be considered.
• Medical and surgical support: Depending on your circumstances, a specialist may recommend fertility treatments (like IUI [intrauterine insemination], or IVF [in vitro fertilisation]), or surgery to remove endometriosis tissue.
• Alternative paths to parenthood: Other routes to building a family include third-party reproduction (such as using donor eggs) and adoption.

A fertility specialist can help you understand which options are most suitable based on your medical history, the severity of your condition, and your future plans.

Why do some people with endometriosis choose to freeze their eggs?

Egg freezing isn't necessary for everyone with endometriosis, but for some people it may be worth considering. Importantly, having endometriosis does not automatically mean you will struggle to conceive; in fact, more than 70% of women with the condition are able to get pregnant naturally (without fertility treatment).

However, for some people, endometriosis can affect the ovaries and, in some cases, reduce ovarian reserve more quickly than expected, especially following surgery to remove endometriomas. If you're not ready to have children but are concerned about your future fertility, freezing your eggs may help preserve the opportunity to use younger eggs later.

Because endometriosis often develops at a very young age, the decision about whether to have children may still be far in the future. For younger people diagnosed with the condition, egg freezing can act as a reassuring “back-up option” for starting a family later in life.

It's also important to remember that fertility naturally declines with age, regardless of whether someone has endometriosis. Age remains one of the biggest factors affecting egg quality and the chance of pregnancy.

A fertility specialist can assess your ovarian reserve using blood tests and an ultrasound scan, as well as looking at how widespread your endometriosis is. With this complete picture, they can help you decide if egg freezing might be appropriate for your personal situation.

While egg freezing cannot guarantee a future pregnancy, it can preserve the quality of younger eggs, providing additional options for having children later in life.

When should you speak to a fertility specialist?

You may benefit from speaking to a fertility specialist if:

• You've been diagnosed with endometriosis and are thinking about having children (now or in the future).
• You're concerned about how endometriosis might affect your fertility.
• You've been trying to conceive without success.
• You're considering egg freezing and would like personalised advice about whether it could be suitable for you.

Seeking advice early doesn't mean you'll need treatment straight away. Instead, it can help you understand your fertility, discuss your options, and make informed decisions.

Final thoughts

Living with endometriosis can be challenging, and managing the painful symptoms is often the immediate priority. While the condition can affect fertility for some people, it doesn't affect everyone in the same way, and many people with endometriosis go on to have successful pregnancies.

Understanding how endometriosis may influence your fertility allows you to make informed choices about family planning, whether that's trying to conceive now, considering fertility preservation, or simply learning more about your reproductive health.

If you'd like to learn more about egg freezing and whether it could be the right option for you, click here.