A shared egg donor program: which is the minimum number of oocytes to be allocated?

Area of Science:

• Reproductive Medicine
• In Vitro Fertilization (IVF)
• Oocyte Donation

Background:

• Shared egg donor programs offer an alternative for recipients needing oocytes.
• Determining the optimal number of oocytes per recipient is crucial for program efficiency and success rates.

Purpose of the Study:

• To determine the minimum number of mature oocytes (MII) required per recipient in a shared egg donor program to achieve successful pregnancy outcomes.
• To evaluate the impact of allocated oocyte numbers on clinical pregnancy rates, miscarriage rates, embryo quality, and embryo cryopreservation.

Main Methods:

• Retrospective analysis of 953 recipients who received at least 4 metaphase II (MII) oocytes between 2006 and 2008.
• Recipients were stratified based on the actual number of MII oocytes received.

Main Results:

• No statistically significant differences in clinical pregnancy rates or miscarriage rates were observed across different oocyte allocation groups.
• Recipients receiving 7 or more mature eggs showed significantly higher rates of top-quality transferred embryos and embryo freezing.

Conclusions:

• A minimum allocation of 4 mature oocytes (MII) appears adequate for achieving satisfactory pregnancy rates in shared egg donor programs.
• While higher oocyte numbers do not significantly impact fresh embryo transfer success, they may enhance embryo quality and cryopreservation potential.