Endometriosis and Fertility: What Every Woman Needs to Know

Endometriosis is one of the most common and yet most consistently under-diagnosed reproductive conditions in women. In Australia, it affects an estimated 1 in 9 women of reproductive age — approximately 830,000 women across the country. And despite being a leading cause of chronic pelvic pain, painful periods, and infertility, the average time from symptom onset to diagnosis in Australia is still an astounding 6.5 years.

That diagnostic delay has real consequences. For women who want to conceive, years of undiagnosed endometriosis can mean years of unexplained infertility, unnecessary suffering, and progressive damage to the reproductive organs. Understanding what endometriosis is, how it affects fertility, and what you can do about it is essential knowledge for any woman navigating the intersection of this condition and her desire to start a family.

What Is Endometriosis — and What Isn't

Endometriosis is a condition in which tissue similar to the endometrium (the lining of the uterus) grows outside the uterus. These deposits of tissue — called lesions or implants — are most commonly found on the ovaries, fallopian tubes, the peritoneum (lining of the abdominal cavity), and the bowel. In severe cases, endometriosis can involve the bladder, ureter, diaphragm, or other distant sites.

Like the normal endometrium, these lesions respond to hormonal fluctuations during the menstrual cycle — thickening, breaking down, and bleeding. But because this blood and cellular debris has nowhere to go, it causes inflammation, scarring (adhesions), and the formation of fluid-filled cysts on the ovaries known as endometriomas (sometimes called "chocolate cysts" because of their dark, old blood content).

It's important to distinguish between endometriosis and adenomyosis, which is a related but distinct condition where endometrial tissue grows within the muscular wall of the uterus itself. Women can have one or both conditions. Both can affect fertility, though through somewhat different mechanisms.

Endometriosis is also not simply "bad periods." This is a significant misconception that has contributed to the years-long diagnostic delay many women experience. While painful periods are the most commonly recognised symptom, endometriosis can present as pelvic pain at any point in the cycle, pain during or after intercourse, pain with bowel movements or urination (particularly during menstruation), fatigue, gastrointestinal symptoms, and infertility — sometimes as the only presenting symptom.

How Endometriosis Affects Fertility: The Mechanisms

Endometriosis is associated with infertility through multiple, interconnected pathways. Understanding how it affects reproductive function helps explain why treatment approaches vary and why there's rarely a simple fix.

Structural damage: In advanced endometriosis (stages III and IV), adhesions and scar tissue can physically distort the anatomy of the pelvis. Fallopian tubes may become blocked, kinked, or unable to pick up eggs released from the ovary. Ovaries may be stuck in abnormal positions, surrounded by adhesions or engulfed by endometriomas. This structural disruption can directly prevent natural conception.

Ovarian damage: Endometriomas on the ovaries don't just cause pain — they actively damage the ovarian tissue. Research has shown that endometriomas are associated with reduced ovarian reserve (fewer eggs), lower antral follicle counts, and decreased anti-Müllerian hormone (AMH) levels. Importantly, surgery to remove endometriomas can further reduce ovarian reserve if not performed with careful technique — making the choice of when and how to operate a significant decision.

Inflammatory environment: Even in mild endometriosis without structural damage, the peritoneal (pelvic) environment is characterised by chronic inflammation. Peritoneal fluid in women with endometriosis contains elevated levels of inflammatory cytokines, activated immune cells, and reactive oxygen species. This toxic environment can impair sperm function, damage eggs, disrupt fertilisation, and interfere with early embryo implantation.

Endometrial receptivity: Growing research suggests that endometriosis affects not just the ovaries and tubes, but the endometrium itself — the lining where an embryo must implant. Studies have found differences in gene expression, immune cell populations, and hormonal responses in the endometrium of women with endometriosis compared to those without, potentially creating a less hospitable environment for implantation.

Egg quality: Women with endometriosis tend to produce fewer eggs in IVF cycles and those eggs may have higher rates of chromosomal abnormalities, though the evidence on the last point is still evolving. The oxidative stress environment within endometriotic ovaries is thought to be a key driver of reduced egg quality.

Diagnosis: Why It Takes So Long and What Can Be Done

The 6.5-year average diagnostic delay in Australia is not unique — similar figures are reported in the UK, USA, and globally. The reasons are complex: symptom normalisation (women being told that painful periods are normal), inadequate medical education on endometriosis, and the fact that standard imaging is limited in its ability to detect the condition.

An ultrasound can identify ovarian endometriomas and sometimes deep infiltrating endometriosis, but it cannot reliably detect superficial peritoneal lesions — the most common form. MRI is more sensitive than ultrasound for deep disease but is not always accessible or ordered. Blood tests (including CA-125, sometimes used as a marker) have poor specificity for endometriosis and are not diagnostic on their own.

The definitive diagnosis of endometriosis requires laparoscopy — a surgical procedure in which a camera is inserted through small incisions in the abdomen to directly visualise the pelvic organs. Biopsies of suspicious lesions confirm the diagnosis histologically. This surgical requirement for diagnosis partly explains the delay, as both patients and doctors may be reluctant to pursue surgery when symptoms could have other explanations.

What can women do to advocate for themselves?

• Track and document your symptoms in detail, including their timing relative to your cycle
• Seek out GPs and gynaecologists with a specific interest in endometriosis
• If your concerns are dismissed, seek a second opinion
• Ask specifically about endometriosis if you have symptoms consistent with it, rather than waiting for it to be volunteered
• In Australia, the Endometriosis Australia website provides resources for finding endometriosis-specialist healthcare providers

Stages of Endometriosis and Fertility Outcomes

Endometriosis is classified by the American Society for Reproductive Medicine (ASRM) into four stages based on the extent and location of disease:

• Stage I (Minimal): Small implants, no significant adhesions. Monthly fecundity (probability of conception per cycle) may be slightly reduced but is closest to normal.
• Stage II (Mild): More implants, typically superficial. Some evidence of reduced fertility but often less than expected based on lesion extent alone.
• Stage III (Moderate): Deep implants, small ovarian endometriomas, some adhesions. Fertility is more significantly affected.
• Stage IV (Severe): Large endometriomas, extensive adhesions, sometimes involvement of bowel or bladder. Fertility is substantially impaired without intervention.

Importantly, the relationship between stage and fertility outcomes is imperfect. Some women with stage IV disease conceive naturally; some with stage I struggle with infertility. This reflects the multiple mechanisms by which endometriosis affects fertility — structural damage correlates with stage, but inflammatory and molecular factors do not always.

Treatment Options When Fertility Is a Priority

Treatment of endometriosis in the context of fertility is nuanced and should be individualised based on the woman's age, the severity of the disease, ovarian reserve, and personal circumstances. The goal is to maximise the probability of pregnancy while minimising further damage to reproductive potential — including the risk of reducing ovarian reserve through surgery.

Surgical treatment: Laparoscopic surgery to remove (excise) or ablate (destroy) endometriotic lesions can improve fertility outcomes in stages I–II disease. A landmark Cochrane review found that laparoscopic surgery doubled the pregnancy rate in women with minimal to mild endometriosis compared to diagnostic laparoscopy alone. For more advanced disease, the picture is more complex.

For endometriomas specifically, the surgical approach is contentious. Cystectomy (removing the cyst wall) may reduce ovarian reserve because the cyst wall is intermingled with healthy ovarian tissue. Draining and ablating the cyst may preserve more ovarian tissue but has higher recurrence rates. The decision should be made in consultation with a specialist, weighing the potential benefit to natural fertility against the risk of reducing ovarian reserve prior to IVF if needed.

IVF: For women with severe endometriosis, advanced age, other fertility factors, or failed natural conception after surgery, IVF is often the recommended path. IVF success rates in women with endometriosis are generally lower than in age-matched women without the condition, reflecting reduced egg numbers and potentially lower egg quality. Pre-treatment suppression with GnRH agonists for 3–6 months before IVF has been shown in some studies to improve outcomes in women with endometriosis.

Endocrine suppression before fertility treatment: Medical treatments for endometriosis (hormonal contraceptives, GnRH agonists, progestins) suppress the disease but also suppress ovulation, making them incompatible with attempting conception. However, a short course of hormonal suppression before IVF may improve the endometrial environment. This approach should be discussed with a fertility specialist.

Nutritional and Lifestyle Support for Endometriosis-Related Fertility

While lifestyle and nutritional interventions don't treat the structural aspects of endometriosis, they have genuine evidence for reducing the inflammatory burden and supporting reproductive function — both of which are relevant to fertility in this context.

Anti-inflammatory diet: Because endometriosis is fundamentally an inflammatory condition, dietary strategies that reduce systemic inflammation have a plausible benefit. The Mediterranean diet — characterised by high intake of vegetables, fruits, legumes, whole grains, fish, and olive oil, with limited processed foods and red meat — has the strongest evidence for anti-inflammatory effects. Studies have found associations between adherence to Mediterranean-style eating and reduced endometriosis risk and symptom severity.

Specific foods with evidence for anti-inflammatory properties particularly relevant to endometriosis include: omega-3-rich fish (salmon, sardines, mackerel), dark leafy greens (spinach, kale), cruciferous vegetables (broccoli, cauliflower, Brussels sprouts), berries, turmeric (curcumin), and green tea (EGCG).

Omega-3 fatty acids: The anti-inflammatory effects of EPA and DHA are directly relevant to endometriosis. Several studies have found that women with endometriosis have lower omega-3 levels and higher omega-6 to omega-3 ratios compared to women without the condition. Supplementation with high-dose fish oil has shown reductions in endometriosis-related pain in some trials.

Antioxidants: The oxidative stress within endometriotic tissue is a key mechanism of damage — to the ovaries, eggs, and surrounding structures. Antioxidant supplementation targeting this mechanism has shown benefits in some studies. Vitamin E and vitamin C together reduced pain scores and inflammatory markers in a clinical trial of women with endometriosis. N-acetylcysteine (NAC), a precursor to glutathione, reduced endometrioma size in one small RCT.

CoQ10: Given the oxidative damage to ovarian tissue in endometriosis and the role of CoQ10 in both antioxidant defence and mitochondrial energy production, this supplement is particularly logical for women with endometriosis-related fertility concerns.

Living With Endometriosis While Trying to Conceive

The psychological burden of endometriosis — managing chronic pain, navigating a healthcare system that has historically dismissed women's pain, and dealing with fertility challenges on top — is substantial. Research consistently finds higher rates of anxiety, depression, and reduced quality of life in women with endometriosis.

Support strategies that have evidence for psychological wellbeing in this context include:

• Peer support: Connecting with other women with endometriosis, through organisations like Endometriosis Australia or online communities, provides validation, practical knowledge-sharing, and emotional support
• Pain management strategies: Heat, TENS (transcutaneous electrical nerve stimulation), physiotherapy specialising in pelvic floor conditions, and psychological approaches like mindfulness can all help manage chronic pain without suppressing ovulation
• Fertility counselling: Navigating treatment decisions for endometriosis with fertility goals in mind is genuinely complex. Fertility counsellors can help with the emotional aspects while specialist medical opinions guide the clinical decisions
• Self-advocacy: Women with endometriosis often need to advocate forcefully for their health. This is exhausting but necessary. Building a medical team you trust — including a gynaecologist with endometriosis expertise and a fertility specialist if needed — is foundational

Frequently Asked Questions: Endometriosis and Fertility

Q: Does having endometriosis mean I definitely won't be able to get pregnant naturally?
A: No. Many women with endometriosis, including those with more advanced stages, conceive naturally. The condition increases the difficulty and time to conception, but it does not eliminate natural fertility for most women, particularly at younger ages and with less severe disease.

Q: Will treating endometriosis surgically improve my chances of pregnancy?
A: For mild to moderate endometriosis, evidence supports that surgical treatment improves pregnancy rates compared to no treatment. For severe endometriosis, the picture is more complex, and proceeding directly to IVF may be recommended to preserve ovarian reserve that could be damaged by repeat surgery.

Q: How does endometriosis affect IVF success rates?
A: Women with endometriosis generally have lower IVF success rates than age-matched women without the condition, due primarily to fewer eggs retrieved and potentially lower egg quality. However, many women with endometriosis do achieve successful pregnancies through IVF, and outcomes are improving with better protocols.

Q: My ultrasound didn't show endometriosis. Does that mean I don't have it?
A: Not necessarily. Standard pelvic ultrasound misses the most common form of endometriosis — superficial peritoneal disease. It can detect endometriomas (ovarian cysts) and sometimes deep infiltrating disease, but a normal ultrasound does not rule out endometriosis. Definitive diagnosis requires laparoscopy.

Q: I have an endometrioma. Should I have surgery before trying IVF?
A: This is one of the most debated questions in reproductive medicine. Surgery may reduce the inflammatory environment but risks reducing ovarian reserve. Many specialists recommend against operating on endometriomas before IVF unless they are very large, growing, or causing symptoms, because of the risk of damaging healthy ovarian tissue. This decision should be made in consultation with a specialist who can assess your specific situation.

Q: Can endometriosis recur after treatment?
A: Yes. Endometriosis has a significant recurrence rate after surgery — studies estimate that 40–50% of women experience recurrence within 5 years if not on hormonal suppression. This is why, for women who want to conceive, the recommendation is often to try to conceive relatively soon after surgery rather than waiting.

Q: Does diet really help endometriosis?
A: While no diet will cure endometriosis, anti-inflammatory dietary approaches have evidence for reducing symptom severity and inflammatory burden. The Mediterranean diet and omega-3 supplementation have the most evidence. Dietary changes are most useful as a complement to — not a replacement for — medical or surgical treatment.

Q: Is endometriosis hereditary?
A: There is a genetic component to endometriosis. Women with a first-degree relative (mother or sister) with endometriosis are approximately 7 times more likely to develop the condition themselves. However, most women with endometriosis don't have an affected relative, and having a family history doesn't guarantee you'll develop it.

Q: Can I get pregnant if I have both endometriosis and diminished ovarian reserve?
A: This combination is challenging but not necessarily insurmountable. The key variables are the extent of the reserve reduction, your age, and the severity of the endometriosis. Early consultation with a fertility specialist is important to assess your specific situation and consider options including IVF, potentially with donor eggs if ovarian reserve is severely affected.