Maximising and Maintaining Fertility in Suspected or Confirmed Endometriosis: A Structured Narrative Review for Clinical Practice.

Endometriosis affects a substantial proportion of women of reproductive age and is a common, often under-recognised contributor to subfertility. Its effects on fertility are multifactorial, and both the disease and its treatment, particularly ovarian surgery, can reduce ovarian reserve. Clinicians are frequently required to balance pain control, restoration of anatomy, assisted reproduction, and the protection of future fertility, often with imperfect evidence. The objective of this review was to synthesise current evidence and guideline recommendations on the interventions and care pathways that most effectively maximise the chance of pregnancy while minimising avoidable loss of ovarian reserve for women who are trying to conceive and those wishing to preserve future fertility. We searched PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), the Cochrane Library and, where accessible, Embase and Scopus, from January 2010 to June 2026, supplemented by landmark earlier trials and by guidelines from the European Society of Human Reproduction and Embryology (ESHRE), National Institute for Health and Care Excellence (NICE), and American Society for Reproductive Medicine (ASRM). Clinical guidelines, systematic reviews, meta-analyses, randomised controlled trials and large prospective cohort studies addressing endometriosis, ovarian reserve, endometrioma surgery, assisted reproduction and fertility preservation were prioritised. This was a structured narrative review and not a systematic review; no formal risk-of-bias scoring or quantitative meta-analysis was undertaken. Age, ovarian reserve, and duration of infertility are the dominant prognostic factors and should drive timing. Excisional surgery for minimal-to-mild disease produces a modest absolute increase in spontaneous conception, whereas ovarian endometrioma cystectomy consistently lowers anti-Müllerian hormone and is the principal iatrogenic threat to ovarian reserve. Assisted reproduction outcomes in women with endometrioma are broadly comparable to those without, and surgery before in vitro fertilisation does not reliably improve live birth; routine cystectomy before treatment is therefore not supported. Medical hormonal therapy controls pain and reduces recurrence, but suppresses ovulation and is not a fertility treatment during attempts to conceive. Oocyte and embryo cryopreservation are reasonable options before bilateral or repeat ovarian surgery and for women delaying conception, but success is age-dependent and not guaranteed. Emerging or investigational approaches-oral gonadotrophin-releasing hormone antagonists, reserve-sparing ethanol sclerotherapy of endometrioma, the Endometriosis Fertility Index as a counselling tool, intraovarian platelet-rich plasma and artificial-intelligence-assisted imaging-are reviewed with appropriate caution. Fertility should be discussed early, at suspicion, not only at confirmation. An individualised pathway that protects ovarian reserve, avoids unnecessary or repeated ovarian surgery, integrates assisted reproduction without delay in higher-risk women, and offers timely fertility preservation is most likely to maximise reproductive outcomes. Access inequities make pragmatic, resource-sensitive pathways a global priority.