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

Area of Science:

• Reproductive Endocrinology
• In Vitro Fertilization
• Oocyte Cryopreservation

Background:

• Oocyte cryopreservation is a key strategy for fertility preservation.
• Triggering final oocyte maturation is critical for successful cryopreservation.
• The optimal trigger strategy for planned oocyte cryopreservation remains debated.

Purpose of the Study:

• To compare oocyte yield and maturation rates between gonadotropin-releasing hormone agonist-only (GnRHa-only) trigger and dual trigger protocols.
• To evaluate the impact of different human chorionic gonadotropin (HCG) doses in dual trigger protocols.
• To assess these outcomes in individuals undergoing planned oocyte cryopreservation with unknown fertility.

Main Methods:

• Retrospective cohort study of 1002 planned oocyte cryopreservation cycles (2010-2023).
• Patients received either GnRHa-only trigger or a dual trigger (GnRH-a with HCG 1500-10,000 IU).
• Key outcomes analyzed: total oocytes retrieved, mature oocytes, and maturity rate, adjusted for covariates.

Main Results:

• GnRHa-only trigger yielded significantly more oocytes retrieved compared to all dual trigger groups (p < 0.02).
• Maturation rate was 10% lower with dual trigger using 10,000 IU HCG versus GnRHa-only trigger (RR=0.9, p=0.003).
• Dual triggers with lower HCG doses (1500-5000 IU) retrieved more oocytes than high-dose HCG dual triggers, but maturity rates were similar.

Conclusions:

• GnRHa-only trigger is associated with higher oocyte yield and maturity rates in planned oocyte cryopreservation compared to dual triggers.
• High-dose HCG in dual triggers may reduce oocyte maturity.
• Prospective studies are recommended to confirm these findings and mitigate bias.