Comparison of ovarian reserve after laparoscopic cystectomy in patients with ovarian endometriosis differ in cyst size: A systematic review and meta-analysis.

Background: Whether cyst size affects ovarian reserve before and after surgery remains controversial.

Objective: The objective of this study is to determine whether cyst size causes differences in pre- and post-ovarian reserve impairment among patients with endometrioma.

Search strategy: PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure were searched from inception to October 13, 2023.

Selection criteria: We included prospective studies comparing the ovarian reserve parameters of patients with endometrioma preoperatively and at different time points postoperatively between large and small groups, determined by self-defined cut-off values in eligible studies.

Data collection and analysis: Bias was assessed using the Newcastle-Ottawa Scale. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used for outcome measures.

Main outcome measure(s): The main outcome measures are serum anti-Müllerian hormone (AMH) and antral follicle count (AFC) preoperatively and at different time points postoperatively (primary and secondary aims).

Main results: Seven trials (603 participants) were included, all of which qualified for meta-analysis. Irrespective of the cut-off values, the SMD showed that the serum AMH level was significantly lower in large groups at 1 month postoperatively (SMD = -0.515 ng/mL, 95% CI [-0.858, -0.172], P = 0.003, $I^2$ = 44.3%). Subgroup analyses indicated that when the cut-off values were limited to 5 cm in diameter, the AMH levels were significantly lower in large groups (SMD = -0.822 ng/mL, 95% CI [-1.605, -0.039], P = 0.040, $I^2$ = 58.3%) 1 month after the surgery, and when cut-off values were limited to 7 cm, even at 3 months postoperatively, the serum AMH levels of patients with large endometrioma were still significantly lower than those with small endometrioma (SMD = -0.531 ng/mL, 95% CI [-0.818, -0.245], P = 0.000, $I^2$ = 0.0%). However, when cut-off values were not limited, the serum AMH levels did not differ significantly (P > 0.05) between the groups preoperatively and at 3, 6, and 12 months postoperatively. Additionally, there were no significant differences (P > 0.05) in the AFC between the groups preoperatively and 1 month postoperatively.

Conclusion: AMH in patients with different endometrioma sizes recovered to the same level at 6 months postoperatively. Our study provides guidance for the clinical prognostic assessment of patients with large endometriomas after laparoscopic cystectomy.

Systematic review registration: CRD42023481967(PROSPERO).