Subtype matters: ovarian endometriosis impairs ovarian reserve and embryo quality—should these patients consider fertility preservation?

Which patients with endometriosis suffer from diminished ovarian reserve as well as impaired embryo quality and therefore could benefit from medical freezing as part of fertility preservation strategies?

This retrospective study analyzed 205 patients who underwent follicle puncture at our center in preparation for IVF/ICSI treatment. All patients with laparoscopically confirmed endometriosis were classified according to rASRM and #ENZIAN. In total, 183 follicle punctures and 168 embryos were evaluated. Anti-Müllerian hormone (AMH) levels, the antral follicle count (AFC), the number of retrieved oocytes as well as the rate of mature oocytes and the fertilization rate were compared among the different subtypes of endometriosis. Embryo quality was assessed by the KIDScore™ on days 3 and 5.

The analyses revealed significant differences in the AFC among patients with peritoneal (mean AFC: 16.43), deep-infiltrating (11.84) and ovarian endometriosis (10.85) (p = 0.006). The largest difference was observed between superficial and ovarian endometriosis (p = 0.004). The number of retrieved oocytes also differed significantly among the subgroups (p = 0.012), with the strongest contrast between deep-infiltrating (11.18) and ovarian endometriosis (8.14). Although the AFC, AMH and number of retrieved oocytes were strongly correlated, AMH alone did not differ significantly between the subgroups. The rate of mature oocytes was the lowest in patients with deep-infiltrating endometriosis but did not reach statistical significance. Patients with endometriomas presented the lowest fertilization rates and KIDScore™ values; however, only the difference in KIDScore™ D5 reached statistical significance (FR: p = 0.077, D3: p = 0.659, D5: p = 0.005).

Endometriosis subtypes differ in their impact on the ovarian reserve. Patients with ovarian endometriosis exhibit a diminished ovarian reserve, reflected by a lower AFC, a lower number of retrieved oocytes and lower number of mature oocytes. Additionally, a lower embryo quality was also observed. These findings could not be replicated in patients with superficial or deep-infiltrating endometriosis. Our study highlights the importance of identifying the specific form of endometriosis. Given that diminished ovarian reserve and recued embryo quality were observed at the time of reproductive therapy, we propose that early elective oocyte cryopreservation may help prevent these adverse outcomes, particularly in patients with ovarian endometriosis. However, additional factors and fertility preservation strategies should be taken into account when considering its indication and fertility preservation strategy in patients with deep-infiltrating or superficial endometriosis.