Endometriosis is a common condition which affects one in seven females and those assigned female at birth. It is a complex condition that affects fertility through inflammatory pathways, impacting ovarian, peritoneal, tubal, and endometrial function. This disruption can hinder folliculogenesis, fertilisation and implantation, potentially leading to infertility.
Endometriosis can be surgically staged as Stage I-IV, and these stages correlate directly with fertility outcomes. In advanced stages (III and IV), endometriosis may cause significant anatomical distortions and adhesions, further complicating oocyte release, folliculogenesis, sperm motility, myometrial contractions, fertilisation and embryo transport.
Treatment approaches
While medical or hormonal therapies are often prescribed for pain management, they do not enhance fertility outcomes in cases of endometriosis-associated infertility. These therapies are therefore not recommended as a treatment for infertility itself. However, they can be useful post-surgery to alleviate pain and reduce recurrence of endometriosis without affecting future pregnancy rates.
Surgical intervention can improve spontaneous pregnancy rates depending on the stage and extent of endometriosis. For patients with endometriosis-associated infertility, surgical options may be beneficial, particularly for those looking to avoid assisted reproductive technology (ART) such as IVF.
Stage I/II endometriosis: Laparoscopic surgery for early-stage endometriosis has been shown to enhance spontaneous conception rates in patients with infertility.
Ovarian endometriomas: Laparoscopic excision of ovarian endometriomas, including cyst wall stripping, sclerotherapy, or plasma ablation, is effective in increasing spontaneous conception rates. Simple drainage of endometriomas is not advised due to a 100% recurrence rate. If attempting conception is not desired immediately following surgery, hormonal therapy may help prevent recurrence.
Deep infiltrating endometriosis (DIE): No substantial evidence supports laparoscopic treatment of DIE to improve fertility, though surgery may be beneficial for symptomatic individuals desiring pregnancy.
For those weighing natural conception post-surgery versus ART, clinicians and patients should collaborate on decisions using the Endometriosis Fertility Index (EFI), which predicts non-ART pregnancy rates after surgery.
Medically assisted reproduction
Medically assisted reproduction provides additional pathways to pregnancy for those with endometriosis-related infertility, particularly when spontaneous conception is unlikely.
Intrauterine insemination (IUI): For patients with Stage I/II endometriosis, IUI combined with ovarian stimulation shows improved pregnancy rates over expectant management. However, the efficacy of IUI in more advanced stages (III/IV) is unclear.
In vitro fertilisation (IVF): IVF is often the preferred option for patients with a low EFI score post-surgery, those with impaired tubal function, or those facing male factor infertility. ART does not increase the risk of endometriosis recurrence, though symptoms may intensify during treatment.
During IVF, oocyte retrieval can be performed with an endometrioma present. Prophylactic antibiotics are sometimes administered to minimise the risk of infection, which
remains low.
Pre-ART hormonal treatment using GnRH analogues has not been clearly shown to improve live birth rates, though it may be beneficial for pain management or reducing endometrioma recurrence when ART is delayed. Likewise, hormonal suppression via combined contraceptive or progesterone-only pills does not enhance live birth rates in ART.
Surgical treatment may serve as an adjunct to ART in certain cases, particularly for pain relief or improved access to follicles prior to oocyte retrieval.
Stage I/II endometriosis: Routine surgery is not recommended for patients planning ART as it does not enhance ART pregnancy outcomes.
Ovarian endometriomas: Surgery should be avoided for endometriomas smaller than 4cm to preserve ovarian reserve. However, it may be offered for pain management or improved accessibility to follicles during oocyte aspiration.
Deep Infiltrating Endometriosis (DIE): Surgical intervention prior to ART should be based on pain severity and patient preference, as current evidence does not indicate reproductive outcome improvement, however studies are limited.
Fertility preservation considerations
Fertility preservation options, such as oocyte freezing, should be considered in patients with ovarian endometriomas due to the potential impact on ovarian reserve. Recurrence of endometriomas that may necessitate repeat surgery could further compromise fertility, making fertility preservation a strategic consideration and one that should be discussed in detail with the patient to ensure they are aware of the pros and cons.
The treatment of endometriosis-associated infertility requires a tailored approach that balances surgical options, assisted reproductive techniques, and preservation strategies. Collaborative decision-making using tools like the Endometriosis Fertility Index allows clinicians and patients to consider all options in a way that best addresses both fertility and quality of life.
Key messages
- Endometriosis disrupts fertility through inflammation and anatomical changes
- Surgery and ART provide fertility options based on endometriosis severity
- Personalised treatment and preservation aid family planning with endometriosis.
Author competing interests – nil