Endometriosis and Infertility: The Connection Most Doctors Miss

Endometriosis is one of the most common, most damaging, and most underdiagnosed conditions affecting women's reproductive health in India. It is estimated to affect approximately 10% of women of reproductive age worldwide — and up to 30 to 50% of infertile women. Yet the average delay between the onset of symptoms and a diagnosis remains five to seven years.

That delay has real consequences — not just for pain and quality of life, but for fertility. Understanding what endometriosis is, how it impairs the ability to conceive, and what treatment options genuinely improve outcomes is essential for any woman who experiences pelvic pain, painful periods, or unexplained infertility.

What Is Endometriosis?

Endometriosis occurs when tissue similar to the inner lining of the uterus (the endometrium) grows outside the uterus. These ectopic deposits are most commonly found on the ovaries, the lining of the pelvis (peritoneum), the fallopian tubes, the uterosacral ligaments, the bowel, and the bladder. Less commonly, endometriosis can be found in the abdominal wall, the diaphragm, or even the lungs.

Like the uterine lining, these deposits respond to hormonal signals — thickening, breaking down, and bleeding with each menstrual cycle. Unlike the uterine lining, this blood has nowhere to drain. The result is local inflammation, scarring (fibrosis), and the formation of adhesions — bands of fibrous tissue that can bind organs together and distort normal pelvic anatomy.

On the ovaries, endometriosis frequently forms cysts called endometriomas, or "chocolate cysts" — so named because they contain old, dark blood with the consistency of chocolate sauce. These cysts progressively damage the surrounding healthy ovarian cortex, reducing the ovarian reserve over time.

How Endometriosis Causes Infertility

Endometriosis impairs fertility through multiple, partially overlapping mechanisms:

• Ovarian damage from endometriomas: As endometriomas grow, they destroy the adjacent ovarian cortex containing primordial follicles (eggs). Women with bilateral endometriomas have significantly lower AMH — often 30 to 50% lower — than women without endometriosis. Each surgical intervention on an endometrioma carries further risk of ovarian damage.
• Anatomical distortion: Severe adhesions can displace the ovaries and fallopian tubes, preventing the tube from capturing the egg after ovulation — a process called pick-up failure.
• Tubal damage and blockage: Periuterine and peritubal adhesions can compress or block the tubes, preventing sperm from reaching the egg or the embryo from travelling to the uterus.
• Hostile pelvic environment: Endometriosis generates a chronic inflammatory state in the pelvis — elevated concentrations of cytokines, prostaglandins, and free radicals in the peritoneal fluid that are toxic to sperm, eggs, and early embryos.
• Endometrial receptivity: Growing evidence suggests that endometriosis may alter the uterine lining's molecular environment, impairing the implantation window and reducing the probability of successful embryo implantation — even in IVF.

Symptoms That Should Raise Suspicion

The classic symptoms of endometriosis include:

• Dysmenorrhoea: Severe, progressively worsening period pain that is debilitating and does not respond to standard pain relief
• Deep dyspareunia: Pain during or after sexual intercourse, particularly with deep penetration
• Chronic pelvic pain: Persistent pain in the pelvis outside of menstruation
• Dyschezia: Pain during bowel movements, particularly around menstruation
• Dysuria: Pain during urination around menstruation (if bladder is involved)
• Infertility: Often the presenting symptom in women with minimal or silent endometriosis

The challenge is that endometriosis symptoms correlate poorly with disease severity. Some women with extensive stage IV endometriosis have minimal pain; some women with limited stage I disease have severe symptoms. And a significant proportion of infertile women have endometriosis diagnosed at laparoscopy without having had any warning symptoms at all.

Diagnosing Endometriosis

Endometriosis cannot be definitively diagnosed from symptoms or blood tests alone. The definitive diagnosis requires laparoscopy — direct visualisation of the pelvis under general anaesthesia — with biopsy of suspicious deposits for histological confirmation.

Transvaginal ultrasound can detect endometriomas (typically appearing as homogeneous low-level echoes on ultrasound) and deep infiltrating endometriosis of the rectovaginal septum in experienced hands — but it cannot detect peritoneal deposits or early-stage disease. A normal ultrasound does not exclude endometriosis.

MRI can provide additional anatomical detail, particularly for deep infiltrating disease, but is not a substitute for laparoscopy in definitive diagnosis.

The Staging System

Endometriosis is staged using the revised ASRM (American Society for Reproductive Medicine) classification, from Stage I (minimal, superficial deposits) to Stage IV (severe, with endometriomas, dense adhesions, and significant anatomical distortion). Critically, stage does not directly predict fertility impact — some Stage I patients have severe infertility; some Stage IV patients conceive with minimal intervention.

Treatment Options for Endometriosis-Related Infertility

Laparoscopic Surgery

Surgical removal of endometriosis deposits — particularly excision rather than ablation (burning) — reduces inflammation, restores anatomy, and can improve natural conception rates in appropriately selected patients. For endometriomas, careful cystectomy (removing the cyst wall while preserving ovarian tissue) is the standard. The key caveat: every operation on an endometrioma risks removing healthy ovarian tissue and further reducing AMH. This risk must be weighed against the benefit.

Dr. Sunita Tandulwadkar has more than 35 years of advanced laparoscopic surgery experience, with a specific focus on fertility-preserving endometriosis excision — maximising disease removal while minimising ovarian damage.

IVF for Endometriosis

IVF bypasses the hostile pelvic environment — fertilisation and early embryo development occur in the protected laboratory environment, not in the inflamed peritoneal cavity. For women with moderate to severe endometriosis, significantly reduced ovarian reserve, older age, or failure to conceive after surgery, IVF is typically the most effective path to pregnancy.

Women with endometriosis undergoing IVF often require careful protocol selection — suppression with GnRH agonists before stimulation is sometimes used to reduce the inflammatory load on the pelvic environment before egg collection.

Surgery vs IVF First: The Critical Decision

The most nuanced clinical decision in endometriosis management is whether to operate before IVF or proceed directly to IVF. The answer depends on age, AMH, the severity of the disease, previous surgical history, and specific anatomical features. In a younger woman with significant pelvic distortion and adequate reserve, surgery first may be appropriate. In an older woman with low AMH and an endometrioma, further surgery may compromise already-limited reserve — making direct IVF the better option.

This decision should never be made by a surgeon without IVF experience, or by an IVF specialist without surgical experience. At Solo Clinic, both perspectives are held in the same clinical team.

Frequently Asked Questions

Q1. Can I get pregnant naturally with endometriosis?

Yes — many women with endometriosis conceive naturally, particularly those with mild stage I to II disease, no tubal damage, and no significant endometriomas. The fertility impact correlates poorly with staging. Women with minimal endometriosis and no other fertility factors often conceive without intervention. Women with moderate to severe disease, endometriomas, or structural damage to the tubes or ovaries typically need medical or surgical assistance.

Q2. Should I have surgery to remove my endometrioma before IVF?

This is one of the most debated questions in reproductive medicine. The risk of further ovarian damage from surgery is real — and the evidence that operating on endometriomas improves IVF outcomes is mixed. For endometriomas larger than 4 cm causing symptoms or impeding follicle access at collection, surgery may be appropriate. For smaller endometriomas in older patients with limited reserve, the risk-benefit ratio often favours proceeding directly to IVF. This decision requires specialist judgment.

Q3. Will endometriosis come back after surgery?

Yes — recurrence rates are significant. Within 5 years of surgery, approximately 20 to 30% of patients have symptomatic recurrence. Long-term hormonal suppression (combined oral contraceptive pill, dienogest, or the Mirena IUS) after surgery is recommended for women not immediately trying to conceive, to reduce recurrence risk. For women who conceive after surgery, the hormonal environment of pregnancy itself suppresses endometriosis activity.

Q4. Does endometriosis affect the baby once I conceive?

The pregnancy itself is not directly affected by endometriosis once conception has occurred. Women with endometriosis have slightly higher rates of certain obstetric complications — including small-for-gestational-age babies, preterm birth, and placental complications — but the absolute risks are modest. Close antenatal monitoring is recommended.