Oocyte donation: not all oocyte cryobanks are the same

Area of Science:

• Reproductive Medicine
• Embryology
• Infertility Treatment

Background:

• Vitrified oocyte donation is a key assisted reproductive technology.
• The source cryobank may influence the efficacy of donated oocytes.
• Understanding cryobank variability is crucial for optimizing fertility treatments.

Purpose of the Study:

• To investigate whether the cryobank of origin affects the efficacy of imported vitrified oocytes.
• To compare cumulative live birth delivery rates (CLBR) across different Spanish oocyte cryobanks.
• To identify predictors of successful oocyte donation outcomes.

Main Methods:

• A longitudinal cohort study of 249 oocyte warming cycles from 200 recipients (January 2016-July 2020).
• Vitrified oocytes were sourced from three Spanish cryobanks.
• The primary outcome was the cumulative live birth delivery rate (CLBR) per completed oocyte warming cycle.

Main Results:

• Overall CLBR was 47.0%, but varied significantly by cryobank: 31.2% (cryobank 1) vs. 56.0% (cryobank 2) and 50.8% (cryobank 3).
• Survival of four or more oocytes post-warming was the strongest predictor for delivery.
• Cryobank 1 showed a significantly lower proportion of cycles with four or more survived oocytes and lower CLBR compared to cryobanks 2 and 3.

Conclusions:

• The efficacy of imported vitrified oocytes is demonstrably affected by the cryobank of origin.
• Fertility centers should internally evaluate cryobank results before collaboration.
• Implementing measures to maximize treatment efficacy based on cryobank performance is recommended.