The Alpha consensus meeting on cryopreservation key performance indicators and benchmarks: proceedings of an expert meeting.

This proceedings report presents the outcomes from an international workshop designed to establish consensus on: definitions for key performance indicators (KPIs) for oocyte and embryo cryopreservation, using either slow freezing or vitrification; minimum performance level values for each KPI, representing basic competency; and aspirational benchmark values for each KPI, representing best practice goals. This report includes general presentations about current practice and factors for consideration in the development of KPIs. A total of 14 KPIs were recommended and benchmarks for each are presented. No recommendations were made regarding specific cryopreservation techniques or devices, or whether vitrification is 'better' than slow freezing, or vice versa, for any particular stage or application, as this was considered to be outside the scope of this workshop.