Egg Quality – What It Really Means and How to Support It

When it comes to fertility, we often hear that “it’s all about age”. While it’s true that egg quality tends to decline over time, that’s far from the whole story. The health of your eggs isn’t fixed; it’s shaped by a combination of biology, lifestyle, and environment. Understanding what “egg quality” really means can help you make sense of why certain changes truly can make a difference.

What do we actually mean by egg quality?

When I discuss egg quality, I'm referring to how healthy an egg is on a cellular level. Things like whether it has the right number of chromosomes, or enough energy to support fertilisation and early embryo development. When IVF clinics talk about egg quality, especially from the lab side of things, it may often be referring to what the eggs looked like down the microscope; dark, grainy, vacuoles etc. These are different factors, but potentially related at times.

Every egg is packed with mitochondria, tiny energy-producing structures that power the early stages of development before the embryo can rely on its own metabolism. If those mitochondria aren’t functioning well, the egg may not mature properly or fertilise successfully. This is an example of the cellular level of functioning, and what I'm really interested in.

In practical terms, egg quality influences whether an egg can:

• mature and be released during ovulation

• be fertilised by sperm

• divide normally and form a viable embryo

• implant successfully in the uterus

So when we talk about improving egg quality, what we’re really doing is optimising the environment in which these energy-producing processes take place.

Age and the biology of egg ageing

Women are born with all the eggs they’ll ever have, and over time both the number and quality naturally decline. This is partly due to oxidative stress, a gradual build-up of cellular damage, and partly due to the natural ageing of mitochondria.

However, while we can’t change chronological age, we can influence the biological environment surrounding those eggs. Supporting mitochondrial health, reducing inflammation, and providing key nutrients all help maintain the energy and stability the eggs need to function well.

How lifestyle influences egg quality

Modern life can work against our eggs in subtle but significant ways.

• Poor diet: Diets high in ultra-processed foods, trans fats, and refined carbohydrates may increase oxidative stress and reduce antioxidant availability.

• Alcohol and smoking: Both increase free radical production and damage mitochondrial DNA.

• Stress: Chronic stress hormones (especially cortisol) may disrupt communication between the brain and ovaries and impair hormone balance.

• Sleep and circadian rhythm: Irregular sleep patterns affect hormone release and egg maturation.

• Toxin exposure: Some environmental chemicals (e.g. BPA, phthalates) can interfere with hormone signalling and follicular development.

On the positive side, a balanced diet rich in antioxidants, stable blood sugar levels, regular movement, adequate sleep, and stress reduction all help create a more supportive internal environment.

Key nutrients for egg health

Certain nutrients play particularly important roles:

• CoQ10 – supports mitochondrial energy production and may improve egg maturation.

• Omega-3 fatty acids – help reduce inflammation and support egg membranes.

• Folate (and other B vitamins) – essential for DNA synthesis and repair.

• Zinc and selenium – act as antioxidants and are involved in oocyte development.

• Vitamin D – supports hormone regulation and ovarian function.

Focusing on real food sources (such as oily fish, colourful vegetables, legumes, nuts, and seeds) provides a balanced range of these nutrients in a form your body recognises.

The 90-day window

Each egg takes around three to four months for it's final maturation before it’s released at ovulation / collected in an ART procedure. This means the conditions you create now can influence the quality of the eggs that will be released / collected in three cycles’ time.

That’s why a minimum “90-day window” is so important; it’s an opportunity to nourish your body during the phase when the eggs are developing, and to put in place habits that can support the next cycle and beyond.

Egg quality, conception, and epigenetics

One of the most fascinating areas of research is epigenetics = the study of how environmental and lifestyle factors influence which genes are switched on or off.

Your eggs carry not only genetic material, but also epigenetic markers that help regulate early development. These markers can be influenced by diet, stress, toxins, and overall metabolic health. This means the environment around your eggs doesn’t just affect your chance of conceiving, it can also shape aspects of your future child’s health.

There’s even evidence that these epigenetic influences can persist into future generations. In other words, the nourishment and care you give yourself now may ripple forward in ways that extend far beyond this moment.

Personally, I find that mind blowing!

Putting it all together

Improving egg quality isn’t about quick fixes or chasing perfection. It’s about consistency; creating a steady, supportive environment through daily habits. Prioritising nutrient-dense foods, regulating blood sugar, moving your body, managing stress, and allowing for rest all play a role.

You can’t control the number of eggs you have left, but you can absolutely influence the health of the eggs you’re about to release.

Next step: I’ve created a simple Egg Quality Support Checklist to help you focus on the key nutrients and habits that make the biggest difference. You can download it free at the end of the month — make sure you’re subscribed to my newsletter so you don’t miss it. Click here to get on my newsletter list and also receive a free 'Fertility testing guide.'

Hope you've found this information helpful!