What this card shows
The Embryo development rate (day 2 - 4 or more cells) card shows what share of normally fertilized oocytes had reached four or more cells by Day 2, month by month.
Four cells on Day 2 is the on-schedule milestone. An embryo that has divided but is still at two or three cells is developing slowly, which is associated with a lower chance of reaching a usable blastocyst.
There are three lines:
Day 2 development rate: your monthly rate.
Excluding discarded embryos: the same rate with discarded embryos left out.
Competency: the Vienna Consensus competency level, 50% or above.
Excluding discarded embryos is the dotted line, shown for contrast. It answers the same question while leaving out any that the lab later discarded.
The two lines together tell you how much of your result rests on embryos that were discarded afterwards. The headline is the one to read and the one the reference lines apply to, because the Vienna Consensus fixes this denominator at the point of assessment, before any disposal decision has been made, and it declines to set benchmarks for measures that depend on what a lab chooses to discard or freeze. The dotted line therefore has no competency or benchmark applied to it.
The Vienna Consensus publishes only a competency level for this measure, not a higher benchmark, so this card carries a single reference line rather than two.
Reading the card
The denominator is normally fertilized oocytes (2PN at the Day 1 check) that were actually graded on Day 2. Embryos with no Day 2 grading on file are left out, as are Day 2 entries recorded as degenerated or as non-assessments.
This is a deliberate departure from the strict Vienna formula, which uses all normally fertilized oocytes as the denominator. Most labs now grade at Day 5 rather than Day 2, so the strict denominator would be dominated by embryos nobody looked at rather than by embryos that developed slowly.
The practical consequence: if your lab grades only a subset of embryos at Day 2, this card describes that subset. It is not a whole-cohort figure.
The Competency line is a flat reference line from the Vienna Consensus, not a measurement from your lab.
Hover any point to see the exact figure.
Read this with Cleavage rate (day 2 - any cleavage) on the same tab. That card asks whether the embryo divided at all, this one asks whether it divided on schedule. A healthy cleavage rate alongside a weak four-cell rate points to slow development rather than to failure.
The card lives on the Laboratory performance (Vienna consensus KPIs) dashboard, on the Embryo Development tab, and responds to the filters at the top:
Date: change the time window. It scopes by the date of fertilization, and defaults to the past 6 months plus the current month.
Clinic: focus on one or more locations, if your organization has several.
Treatment type, Age at cycle start and BMI: narrow to a subset of cycles.
Where this data comes from
Both halves of this card come from the Culture tab of the patient's Cycle page: the Day 1 observation carries the pronuclei grading that puts an embryo into the cohort, and the Day 2 observation carries the cell count.
The cell count is what this card reads, so a Day 2 entry recorded without one cannot be scored. Consistency in when the Day 2 check happens also matters here: this measure is time-sensitive, and an observation logged several hours late will read as further along than a same-time comparison would.
Opening this card
In wawa, open Insights from the sidebar, then go to Standard Reports → Laboratory Performance → Laboratory performance (Vienna consensus KPIs). Select the Embryo Development tab. The Embryo development rate (day 2 - 4 or more cells) card is on it.