Reproductive outcomes after expectant management and 5- versus 15-minute laparoscopic ethanol sclerotherapy for ovarian endometriomas: a retrospective cohort study.

Background: Laparoscopic ethanol sclerotherapy is a fertility-preserving alternative for ovarian endometriomas, but the appropriate ethanol exposure duration remains uncertain. We compared expectant management with 5- and 15-minute ethanol retention protocols. Methods: This retrospective cohort study included 333 infertile women with ovarian endometriomas ≥4 cm and complete cumulative reproductive follow-up: expectant management (n=125), 5-minute (n=124), or 15-minute (n=84) laparoscopic ethanol sclerotherapy. Multinomial propensity scores and inverse probability of treatment weighting (IPTW) balanced prespecified baseline covariates. The primary outcome was complete cumulative live birth; secondary outcomes included cumulative clinical pregnancy, embryological outcomes, and serum AMH changes. Additional sensitivity analyses examined FSH and adenomyosis, calendar year, male factor, and an analysis retaining all 357 clinically eligible women. Results: After primary weighting, all prespecified covariates were balanced (maximum absolute standardized mean difference, 0.094). Cumulative clinical pregnancy rates were 48.4%, 78.2%, and 58.1%, and cumulative live birth rates were 42.7%, 73.0%, and 50.8% in the expectant, 5-minute, and 15-minute groups, respectively (both overall P<0.001). Compared with expectant management, the 5-minute protocol was associated with higher odds of clinical pregnancy (OR = 3.84, 95% CI 1.86-7.93; P<0.001) and live birth (OR = 3.63, 95% CI 1.80-7.30; P<0.001), and with higher odds than the 15-minute protocol (OR = 2.60, 95% CI 1.13-6.00; P = 0.020; and OR = 2.62, 95% CI 1.18-5.81; P = 0.013). The 15-minute protocol did not differ significantly from expectant management. Doubly robust analyses were consistent. In the expanded sensitivity analyses and the additional sensitivity analysis retaining all 357 clinically eligible women, the direction of the primary outcome associations was also unchanged. The proportion of cycles yielding no transferable embryo was lower in the 5- and 15-minute groups than in the expectant group (10.7% and 9.4% vs. 32.8%; overall P<0.001). The relative AMH decline was greater after the 15-minute than the 5-minute protocol (-23.7% vs. -8.1%; P = 0.003). Conclusions: In this retrospective cohort, the 5-minute protocol was associated with higher cumulative pregnancy and live birth rates than expectant management and the 15-minute protocol. Both protocols were associated with fewer cycles yielding no transferable embryo than expectant management, whereas 15-minute retention was associated with a greater AMH decline. These findings are hypothesis-generating and require prospective randomized confirmation.