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Mr Parijat Bhattacharjee, Private Consultant Gynaecologist, Harrow, Brentford, Northwood, London, UK / Media / Videos » Endometrioma & Fertility: RCOG Scientific Impact Paper 55

Endometrioma & Fertility: RCOG Scientific Impact Paper 55

Endometrioma & Fertility: RCOG Scientific Impact Paper 55
Posted on: 03-Jul-2026

This video, titled "Endometrioma & Fertility: RCOG Scientific Impact Paper 55" by Gynae Consultant, reviews the Royal College of Obstetricians and Gynaecologists (RCOG) Scientific Impact Paper No. 55 (published September 2017). The video details how endometriomas (endometriotic cysts on the ovaries) alter fertility and breaks down the clinical debates surrounding surgical removal versus proceeding directly to In Vitro Fertilization (IVF).

Prevalence and Causes

  • Endometriosis Background: Endometriosis is a chronic inflammatory condition affecting 6% to 10% of women of reproductive age, with a much higher prevalence among those experiencing infertility.
  • Endometrioma Frequency: Among women with moderate-to-severe endometriosis, 17% to 44% develop ovarian endometriomas.
  • Pathogenesis: A leading explanation remains retrograde menstruation, where lining cells flow backward through the fallopian tubes into the pelvic cavity. If the host immune system fails to clear these cells, they implant. During ovulation, a breach on the ovarian surface allows this tissue to form an internal cyst.

How Endometriomas Impair Fertility

The severity of endometriosis correlates strongly with decreased fertility. Endometriomas affect reproduction through three primary mechanisms:

  • Pelvic Inflammation: The condition spikes the presence of macrophages, mast cells, T-cells, and natural killer cells in the peritoneal fluid, which alters growth factors and chemokines, compromising egg (oocyte) quality and function.
  • Follicular Fluid Alteration: Within the ovary, endometriomas trigger elevated levels of prostaglandins and interleukin-6 (IL-6), while reducing vascular endothelial growth factors. This harms embryo quality and lowers implantation success.
  • Diminished Ovarian Reserve: The structural presence of a cyst stretches ovarian tissue, generating oxidative stress, free iron release, and subsequent fibrosis. This reduces the Antral Follicle Count (AFC), drops Anti-Müllerian Hormone (AMH) levels, and raises Follicle-Stimulating Hormone (FSH)—a decline that worsens drastically if a patient undergoes bilateral surgery.

Spontaneous Conception vs. Surgery

  • Natural Conception Rates: Observational data reveals that women with an untreated, unilateral (one-sided) endometrioma still have a 43% chance of conceiving naturally within six months. The affected ovary ovulates just as frequently as the healthy one.
  • Surgical Approach: If physical distortion of pelvic anatomy is blocking conception, surgery helps. When a surgical approach is chosen, randomized controlled trials show that a cystectomy (complete excision of the cyst wall) yields lower recurrence and higher pregnancy rates than simple drainage and coagulation. However, patients must weigh this against the post-surgical drop in AMH.

Impact on IVF and Modern Guidelines

Systemic reviews show that the absolute pregnancy, miscarriage, and live birth rates for patients who successfully complete an IVF cycle are essentially identical, whether or not they have an active endometrioma. (Though a decreased response to stimulation may occur if a unilateral cyst is ≥ 3 cm).

The Pre-IVF Surgery Debate

According to the European Society of Human Reproduction and Embryology (ESHRE) guidelines, performing a cystectomy on a unilateral endometrioma ≥ 3 cm does not improve final IVF pregnancy or live birth rates. Therefore, surgery prior to IVF is only recommended if the patient experiences:

  • Severe, unmanageable pelvic pain.
  • Clinical suspicion of malignancy (though the lifetime malignancy risk of an endometrioma is very rare, around 1%).
  • A cyst location that physically blocks a clinician's needle access to healthy follicles during egg retrieval.

Clinical Management Summary

ESHRE guidelines advise an individualized, holistic strategy. Clinicians should skip pre-IVF surgery and go directly to IVF if a patient meets any of these criteria:

  • Advanced maternal age.
  • Low baseline ovarian reserve.
  • Bilateral (both sides) ovarian endometriomas.
  • A history of previous ovarian surgeries.
  • The patient is entirely asymptomatic of severe pain.

Pre-IVF surgery should generally be reserved for young women with a single, large cyst, severe symptoms, and a completely normal ovarian reserve.