Is endometrioma-associated damage to ovarian reserve progressive? Insights from IVF cycles

OBJECTIVE: The relation between endometriomas and damage to ovarian reserve remains controversial. In this study, we hypothesized that this damage may not be present at the time of endometrioma formation but may conversely gradually develop over time. STUDY DESIGN: To investigate the possibility of a time-related detrimental effect of endometriomas on ovarian reserve, we retrospectively selected 29 women with unilateral cysts who underwent at least two IVF cycles at least 6 months apart and evaluated ovarian responsiveness over time. Women were excluded if they conceived, developed new endometriomas or necessitated new medical or surgical therapies for endometriosis during the interval between the two cycles, RESULTS: The mean±SD of the diameter of the endometriomas was 26±8mm. Most women (n=25) had only one endometrioma. In the first cycle, the number of developing follicles in the affected and contralateral intact gonads was 4.9±2.5 and 5.9±2.4, respectively (p=0.10). In the second cycle, it was 5.0±2.9 and 6.0±2.8, respectively (p=0.13). The median (Interquartile Range) proportion of follicles developing in the affected ovaries in the first and second cycles was 44% (31-58%) and 44% (35-55%), respectively (p=0.97). Subgroup analyses according to the duration of the time interval between the two assessments, the dimension of the endometriomas and the history of previous surgery for endometriosis did not show subgroups at significant risk of time-related damage. CONCLUSIONS: We failed to observe an endometrioma-related reduction of ovarian responsiveness with time. However, evidence from larger series obtained in women carrying larger cysts and enrolled for longer time period of time are required for a definitive conclusion.