As you may recall from the last few lessons, many crucial steps in the IVF process are completed by a clinic’s laboratory. There is a wide range in laboratory quality, and being treated at a clinic with a world-class laboratory can double a patient’s chances of success during any given IVF cycle.
We think of the laboratory as a mill because its workflow is linear: it must fertilize eggs, cultivate embryos, occasionally be able to biopsy those embryos for genetic testing, and then be able to freeze embryos (or eggs) and thaw them for future use. The continuum, along with rates of mere “competence” and “excellence” look something like the chart below. Ultimately, under the best circumstances, patients should be treated at a clinic with a laboratory that can:
Fertilize at least 75 - 80% of mature retrieved eggs, depending upon their fertilization technique (higher for ICSI)
Grow 60% of fertilized eggs into blastocyst embryos (or 70% to cleavage stage embryos)
Perform successful PGS biopsy and in 95% of embryos collect enough cells that the sample can be properly read
Freeze embryos and have 99% of blastocysts (or 90% of cleavage stage embryos) thaw intact
It’s crucial that a clinic’s laboratory operates 7 days a week and has multiple embryologists on staff. In circumstances where patients had to wait for the laboratory to re-open on Monday, success rates were needlessly lower, as you can see in the study below.