How to Improve Egg Maturity and What It Really Means in IVF
IVF is hard, and I get a lot of questions about it. Often, people start an IVF cycle not fully understanding what to expect. Today, I want to focus on egg maturity—what it is, why it matters, and strategies to improve it during your IVF cycle.
Why Egg Maturity Matters
One of the most important factors we control in IVF is how many mature eggs we can retrieve. If your cycles aren’t yielding as many mature eggs as expected, the question is: can we do better?
Many people go through the same protocol repeatedly without adjustments. Understanding egg maturity helps you advocate for the best protocol for your body, not just following the same steps over and over.
What Is Egg Maturity?
Think of your ovary like a vault containing all the eggs you’ll ever have. Each month, a group of eggs comes out of the vault and grows inside follicles. The brain releases FSH (follicle-stimulating hormone) to help an egg grow.
In a natural cycle, usually one egg reaches maturity and ovulates, while the rest die off.
The number of eggs released each month depends on factors like age, ovarian reserve, hormone use, autoimmune conditions, endometriosis, or past chemotherapy/radiation.
Ovarian Reserve
Ovarian reserve is a term we use to describe how many eggs remain in the vault. While we can’t know the exact number, we categorize it as:
Very high
High
Normal
Low
Critically low
Undetectable
We assess ovarian reserve using:
Antral Follicle Count (AFC) – the eggs “outside the vault” visible on ultrasound.
AMH (Anti-Müllerian Hormone) – a blood test that reflects the quantity of eggs outside the vault.
Together, these tests give us an idea of how many eggs you might retrieve in an IVF cycle.
IVF: Maximizing Egg Maturity
The goal of IVF is to help all the eggs available in a given month reach maturity, something your body normally resists.
We do this by:
Suppressing the natural brain-ovary connection
Stimulating the eggs with hormones
Stimulation
Most stimulation involves FSH injections, sometimes combined with LH. These medications “feed” your eggs to help them grow. Other add-ons may include:
Human growth hormone
Omnitrose
Clomid or letrozole (in minimal stimulation cycles)
The idea is to get all eggs in the cohort to grow together, giving the best chance for mature eggs.
Suppression
Different protocols use hormones to temporarily suppress FSH, so eggs are “hungry” before stimulation. This improves the likelihood that all eggs in the cohort mature at the same pace.
Some protocols include:
Birth control pills or progesterone/estrogen before the cycle
Testosterone pre-treatment
Lupron (for downregulation or flare protocols)
Choosing the right protocol for your body is critical for egg maturity.
How We Define a Mature Egg
In IVF, maturity is measured by:
Size: 15–20 mm
Hormone production: 150–200 picograms of estrogen per follicle (though this varies with some medications)
Eggs are categorized as:
M2 (mature, fertilizable)
M1 (nearly mature, just missed the last step of meiosis)
Germinal vesicles (very immature)
Degenerated (over-mature or post-mature)
We evaluate not just how many eggs were retrieved, but their stage of maturity to make adjustments in your next cycle.
Ask the Right Questions
If your clinic isn’t using ICSI (intracytoplasmic sperm injection), you may not know egg maturity. ICSI allows us to strip outer cells and see maturity clearly.
Questions to ask your fertility team:
How many eggs were mature?
Of the immature eggs, what stage were they in (M1, GV, degenerate)?
What changes can we make to improve maturity next cycle?
Understanding these details helps you make informed decisions about your IVF protocol and increases your chances of success.
Egg maturity is one of the few aspects of IVF we can influence. By knowing what it is, why it matters, and how protocols impact it, you can advocate for the best possible outcome for your cycle.
