Less is more: assessing trigger types in planned oocyte cryopreservation cycles.

Purpose: To compare oocyte yield and maturation with dual vs. agonist-only trigger for individuals with unknown fertility undergoing planned oocyte cryopreservation.

Methods: Retrospective cohort study of 1002 planned oocyte cryopreservation cycles among 864 patients from January 2010 to March 2023 who received gonadotropin-releasing hormone agonist-only (GnRHa-only) trigger vs. "dual trigger" or GnRH-a with human chorionic gonadotropin (HCG) 1500-10,000 IU. The main outcomes were total number of oocytes retrieved, mature oocytes, and maturity rate.

Results: After adjusting for age, anti-Müllerian hormone, body mass index, antral follicle count, and max gonadotropin dose, all dual trigger groups had significantly lower oocytes retrieved compared with the GnRHa-only trigger (p-values < 0.02). Additionally, the maturation rate was 10% lower in dual trigger with HCG 10,000 IU compared to GnRH agonist-only trigger (rate ratio = 0.9, p = 0.003). Dual triggers with lower doses of HCG (1500 and 5000 IU) had higher amounts of oocytes retrieved than dual trigger with HCG 10,000 IU, but there was no difference in maturity rate within dual triggers.

Conclusion: In a cohort undergoing planned oocyte cryopreservation, the GnRHa-only trigger had higher oocyte yield compared to dual triggers after adjusting for age, anti-Müllerian hormone, body mass index, antral follicle count, and gonadotropin dosing. GnRHa-only triggers have a higher maturity rate than a dual trigger with high HCG. A prospective study is needed to evaluate this further to remove treatment assignment bias.