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IVF polyspermy rate - by oocytes retrieved

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Written by Andrew Manderson

What this card shows

The IVF polyspermy rate - by oocytes retrieved card shows how many oocytes were fertilized by more than one sperm, as a share of every oocyte collected on the cycle, month by month. It covers conventional IVF only, where oocytes and sperm are placed together in a dish.

Polyspermy is identified at the Day 1 check by counting pronuclei (PN). A pronucleus is a visible nucleus in the newly fertilized oocyte. Two, 2PN, is normal. Three or more means more than one sperm got in, and the resulting embryo is not viable.

There are three lines:

  • Polyspermy rate: your monthly rate.

  • Average for selected period: your rate across the whole date range, drawn as a dashed line.

  • Benchmark: the Vienna Consensus benchmark, below 6%.

Average for selected period adds up every oocyte with three or more pronuclei in the date range and divides by every oocyte retrieved on those cycles, so a busy month counts for more than a quiet one. Because this rate is normally low, the average gives a steadier read of the whole period than any single month. It follows every filter at the top of the dashboard.

This is one of the cards where lower is better.

Reading the card

This card is the whole-cycle view of the same measurement as IVF polyspermy rate - by embryos inseminated on the same tab. The two share a numerator and differ only in the denominator:

  • This card counts every oocyte retrieved on the cycle, including oocytes that were stripped, immature, or otherwise never inseminated.

  • The inseminated version counts only the oocytes placed in the IVF dish.

Because the denominator here is larger, this card always reads lower. That is by design, not a discrepancy between the two.

Both cards count an oocyte even if it was later discarded. An abnormally fertilized oocyte is usually discarded soon afterwards, so leaving those out would understate how often polyspermy is happening.

  • The benchmark is defined against the inseminated denominator, so use the other card for benchmark comparison. On this card, treat the Benchmark line as context rather than as a pass mark.

  • Hover any month to see its exact rate and the average for the period.

  • Because the rate is normally low, single months can look volatile when cycle volumes are small. Read the trend across several months.

The value of this view is that it tells you what share of the oocytes a patient actually gave you were lost to polyspermy, which is closer to how a patient experiences the cycle than the dish-level rate is.

The card lives on the Laboratory performance (Vienna consensus KPIs) dashboard, on the Fertilization Performance 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

Everything here comes from the Culture tab of the patient's Cycle page. The number of oocytes collected is entered on the aspiration record, the insemination is recorded as a fertilization event, and the Day 1 observation on each oocyte carries the pronuclei grading.

Because this card's denominator is the retrieval count, an accurate oocyte count on the aspiration matters as much here as the Day 1 gradings do.

Opening this card

In wawa, open Insights from the sidebar, then go to Standard Reports → Laboratory Performance → Laboratory performance (Vienna consensus KPIs). Select the Fertilization Performance tab. The IVF polyspermy rate - by oocytes retrieved card is on it.

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