Key Performance Indicators
The Vienna consensus concluded that there are 12 KPIs that might be considered integral to a QMS since they encompass the most important steps within the IVF lab process (Figure 3).
Since there is a tendency among some practitioners to include triploid (three pronucleate; 3PN) and polyploid (four or more pronuclei; ≥ 4PN) zygotes in their calculation of fertilization rates, it is important to note that the recommended KPI for fertilization rate only includes those zygotes displaying two pronuclei (2PN) and two polar bodies (2PB). Since the number of mature oocytes is unknown at the time of insemination by IVF, it is the long held belief of this author that the only way to scientifically and accurately compare IVF and ICSI fertilization rates is for the denominator to be the same for both, in which case this should be the number of COCs retrieved, and that belief is reflected in the same competency and benchmark values provided in Figure 3, which is an amendment from the values recommended by the Vienna consensus.
In much the same way that reporting cycle outcomes per cycle stimulated more faithfully reflects the overall quality of cycle management, reporting normal fertilization rate (number of 2PN + 2PB zygotes) per COC retrieved more faithfully reflects the overall quality of ovarian stimulation, oocyte handling (eg oocytes may be compromised or lost during denudation prior to ICSI but would not be included in assessment of fertilization rate when expressed per MII oocyte injected) and insemination, whether that be via IVF or ICSI. Although insemination procedures may differ, the initial number of COCs and final number of normally fertilized oocytes are equally relevant and it is important to be able to compare this KPI properly using what should be the same benchmark for both IVF and ICSI.
Previously, various KPIs for cryopreservation, including competencies and benchmarks, have been recommended.3 In this respect, it is important to differentiate between cryosurvival and viability.
The cryosurvival and viability of cleavage stage embryos can be determined by the number of intact blastomeres and number of thawed/warmed embryos developing on to the blastocyst stage, respectively. With blastocysts, however, determination of cryosurvival is less straightforward and viability can only be indirectly assessed via the timing and extent of blastocoele reexpansion, and only in those blastocysts exhibiting a collapsed blastocoele on thawing/warming.
There are three different types of indicator, RI, PI and KPI that may be used to monitor and assess the competency and performance of staff and organizations. The recently published list of LPIs provides a useful checklist for the purposes of lab audits and troubleshooting.2