Endometriosis affects around 1 in 9 women and remains one of the most underdiagnosed conditions in women’s health. Up to 30–50% of people with endometriosis experience fertility challenges, and diagnosis is often delayed, taking an average of 7 to 10 years. For some, infertility is the first sign that something isn’t right.
To mark Endometriosis Awareness Month, we spoke with Create Fertility co-founder, fertility specialist and fertility surgeon, Dr Tom Manley, about how endometriosis affects fertility, why diagnosis can take so long, and what really matters when planning a family.
How can endometriosis affect fertility even when it doesn’t cause severe pain?
Dr Tom: Endometriosis is often silent, progressive, and underestimated. It’s not just about pain. At its core, the condition creates a chronic inflammatory environment in the pelvis, which can interfere with ovulation, egg quality, sperm function, and implantation. Over time, it can also alter pelvic anatomy, affecting the ovaries, fallopian tubes, and surrounding structures in ways that make conception more difficult.
From a fertility perspective, the key challenge is that endometriosis doesn’t need to be severe or painful to have a significant impact.
Why is it so hard to diagnose endometriosis?
Dr Tom: Because endometriosis doesn’t behave predictably. Symptoms vary widely, some women experience significant pain, while others have very few or no obvious symptoms at all. Imaging such as ultrasounds and MRIs can also miss endometriosis, particularly in early or more subtle forms of the condition.
At the moment, the most reliable way to diagnose endometriosis is through laparoscopy, which is a form of keyhole surgery. This means that for some patients, it can take time before all the pieces come together. In those cases, a diagnosis may only become clear later, sometimes when fertility challenges prompt a closer look.
What are the stages of endometriosis?
Dr Tom: Endometriosis is usually described in four stages. The stages are based on what we see during surgery, such as how much endometriosis is present, where it’s located and whether there’s scarring or distortion of the pelvis.
What’s important to know is that the stage doesn’t tell the whole story. Someone with early-stage endometriosis can have real fertility challenges, while someone with more advanced disease may have very few symptoms. That’s why we don’t treat a stage number, we treat the person.
What happens if the first symptom of endometriosis is infertility?
Dr Tom: This is more common than people realise. When infertility is the first sign, the disease has often been present for years. In these cases, our focus shifts quickly to understanding ovarian reserve, tubal function, sperm factors and timing. We also consider whether surgical treatment may improve natural fertility or IVF outcomes. The key is not to panic, but also not to delay.
How does endometriosis impact fertility?
Dr Tom: Endometriosis can affect fertility in a few different ways, and it’s rarely just one thing. The condition creates ongoing inflammation, which can affect egg quality, sperm function and implantation. It can also lead to scarring around the ovaries and fallopian tubes or subtle changes in pelvic anatomy that interfere with how everything works together.
On top of that, endometriosis can influence hormonal and immune function. So even when things look mild on the surface, the biology underneath can still make conception more difficult. That’s why the impact on fertility is often a combination of factors rather than a single cause.
Can I still get pregnant with endometriosis?
Dr Tom: Yes, many people do. But the pathway to pregnancy may look different. Some will conceive naturally, others may need surgery, ovulation support or IVF. The most important thing is having a clear, personalised plan.
What is the endometriosis fertility index (EFI)?
Dr Tom: The EFI is a scoring system used after surgery to estimate the likelihood of natural pregnancy. It takes into account age, fertility history, surgical findings and how well the anatomy has been restored.
I use it as a guide, not a guarantee. It helps us decide whether it’s reasonable to try naturally, or whether moving more quickly to assisted reproduction will give the best chance.
Can having a baby fix endometriosis?
Dr Tom: This is a common myth, but no. Pregnancy may suppress symptoms temporarily. However, it doesn’t cure endometriosis. The disease can return, and symptoms can recur. Long-term management still matters, even after a successful pregnancy.
Can you prevent endometriosis?
Dr Tom: Unfortunately, at the moment, no. We don’t fully understand why endometriosis develops in the first place. But what we can do is recognise it earlier, take symptoms seriously and manage it appropriately. That can make a real difference, particularly when it comes to protecting fertility over the long term.
What should you do now if you’re not trying yet?
Dr Tom: If you’re not trying yet, the most important thing is information, not intervention. That means understanding your diagnosis, your ovarian reserve and what your realistic timelines look like. You don’t need to rush into treatment, but you also don’t want to ignore it. Having a plan early gives you options later.
Should you consider egg freezing with endometriosis?
Dr Tom: For some people, yes, it can be a really sensible option. Endometriosis can affect egg quality and ovarian reserve over time, so egg freezing can help preserve options, particularly if pregnancy is a few years away. It’s not right for everyone, but it’s a conversation worth having sooner rather than later.
How long should you try before getting help?
Dr Tom: If you have endometriosis, I wouldn’t usually recommend waiting the full year. If you’ve been trying for six months without success, or sooner if you’re over 35, it’s reasonable to get some guidance. Early advice doesn’t mean early IVF. It just means smarter timing.
Does surgery help or harm fertility?
Dr Tom: It can do both, which is why timing and expertise really matter. Surgery can improve fertility by reducing inflammation and restoring anatomy, but unnecessary or repeated surgery can also affect ovarian reserve. The goal is always to operate when it’s likely to help, not just because endometriosis is there.
Does endometriosis reduce IVF success?
Dr Tom: Endometriosis can affect IVF outcomes, particularly in more advanced disease, but many people with endometriosis still do very well with IVF. Success depends on factors like age, egg quality and prior treatment. The key is tailoring IVF to the individual, rather than treating everyone the same.
What do you want patients to know most?
Dr Tom: That you’re not overreacting, and you’re not alone. Endometriosis is complex, but there are good options and real reasons for optimism. The most important thing is being heard, getting clear advice and having a plan that fits you, not just your diagnosis.
