Glossary · Definition · v2026.3
What Is Egg Maturation?
Egg maturation is the stage when developing eggs become ready for fertilization.
How Egg Maturation Works
During an IVF cycle, follicles grow under the influence of gonadotropin medications. Inside each follicle, an egg (oocyte) undergoes maturation from an immature germinal vesicle stage to a mature metaphase II stage. Only mature eggs can be fertilized. The trigger shot completes the final maturation process approximately 36 hours before egg retrieval.
Why It Matters in IVF
Not all retrieved eggs are mature. Maturity rate varies between patients and cycles. Typical maturity rates range from 75 to 90 percent of retrieved eggs. Immature eggs cannot be fertilized through conventional IVF or ICSI without additional laboratory techniques. The number of mature eggs retrieved is one of the most important predictors of IVF cycle outcome.
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This content defines terminology for educational orientation. It does not constitute medical advice.
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