Retrospective Audit: The Irreversible Change in Ovarian Reserve After Formal Cystectomy for Ovarian Endometrioma

Introduction: Ovarian cystectomy is a common treatment for endometriomas; however, its long-term impact on ovarian reserve remains uncertain. This study aims to evaluate the longterm pattern of serum anti-Müllerian hormone (AMH) levels following cystectomy and to determine whether ovarian reserve recovers or continues to decline over time. Methods: This retrospective study analysed fifty patients who underwent laparoscopic cystectomy for suspected endometriomas, with a final mean follow-up of 23.3 months (95% CI, 20.90–25.80). Serum AMH levels were measured preoperatively, at 6 months postoperatively, and at the final follow- up. Changes in AMH levels were compared between patients with unilateral and bilateral endometriomas. Results: A significant decline in AMH levels was observed postoperatively. Mean AMH decreased from 2.60 ± 0.87 ng/mL at baseline to 1.37 ± 0.39 ng/mL at 6 months (decline of -1.23 ng/mL, P < 0.05) and further to 1.13 ± 0.43 ng/mL at final follow-up (cumulative decline of -1.47 ng/mL, P < 0.05). Patients with bilateral endometriomas experienced a significantly greater reduction in AMH (-2.79 ± 1.98 ng/mL, 72%) compared to those with unilateral endometriomas (-0.77 ± 0.49 ng/mL, 39%) (P < 0.05). Discussion: Cystectomy for ovarian endometriomas reduces symptoms but significantly impairs ovarian reserve, particularly in bilateral cases, as indicated by a sustained drop in AMH levels. Fertility- preserving alternatives, such as hydro-dissection and partial excision with ablation, may limit ovarian damage. Complete excision is reserved for select high-risk cases. Limitations include a small sample size and the absence of a control group. Conclusion: The decline in AMH following ovarian cystectomy is progressive and does not show evidence of recovery in most patients. Bilateral cystectomy has a more profound impact on ovarian reserve than unilateral surgery. Patients should be counselled about the potential long-term effects on fertility, and fertility-preserving strategies should be considered when managing endometriomas in women desiring future conception.