Glossary · Definition · v2026.3
IVF Attrition Funnel
The IVF attrition funnel describes the natural drop-off of eggs and embryos at each stage of the IVF process, from egg retrieval through fertilization, embryo development, and pregnancy. It is one of the most important concepts in fertility planning because it explains why multiple cycles are often required.
How it works
At each stage of IVF, a percentage of eggs or embryos are lost. Not all retrieved eggs will be mature. Not all mature eggs will fertilize. Not all fertilized eggs will develop to blastocyst stage. Not all blastocysts will be chromosomally normal. This is a biological reality, not a failure of treatment.
Why it matters for cost
The attrition funnel is the primary reason IVF costs multiply. If a single cycle produces few euploid embryos, additional cycles may be needed. Understanding the funnel helps families budget for the multi-cycle reality rather than a single-attempt expectation.
Related reference
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This content defines terminology for educational orientation. It does not constitute medical advice.
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