The impact of egg quality on fertility and pregnancy success
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Key takeaways
- Egg quality is about an egg's chromosomal health and its potential to fertilise and develop into a healthy embryo, it isn't something a single test can measure directly
- Egg quality and egg quantity are different things, tests like AMH and antral follicle count estimate how many eggs you have, not how healthy they are
- Age is the biggest driver of egg quality, because the chance of chromosomal errors increases as eggs get older
- Lifestyle changes can support your general health, but they can't guarantee improved egg quality
- If egg quality becomes a concern, there are several paths to discuss with your specialist, including donor eggs, though there's no guaranteed fix
The impact of egg quality on fertility & pregnancy success
Egg quality is one of the most talked-about, yet often misunderstood, concepts in fertility care. In simple terms, egg quality is how likely an egg is to mature properly, fertilise with sperm, and develop into a healthy embryo that can lead to a pregnancy. It reflects the egg’s internal health, including its chromosomes and cellular function, rather than anything visible to the naked eye.
Importantly, egg quality is not something that can be definitively measured with a single test. Clinicians infer it from patterns, like how eggs behave during treatment, how embryos develop, and how the mother’s body responds overall.
Below, we'll cover the importance of egg quality, how it’s assessed (particularly in IVF), what can influence it, and what options exist if egg quality becomes a concern.
What does “egg quality” actually mean?
Egg quality refers to whether an egg has the biological potential to create a healthy embryo. This comes down to three main factors:
- Chromosomes: A healthy egg should contain the correct number (23). Errors can affect embryo development.
- Maturation: The egg must reach the right stage to be fertilised successfully.
- Early development potential: After fertilisation, the egg needs to divide and grow in a coordinated way to form an embryo.
When people talk about “good” or “poor” egg quality, they are usually referring to how well these processes are likely to occur.
Egg quality vs egg quantity (ovarian reserve)
A common point of confusion is the difference between egg quality and egg quantity.
- Egg quantity (ovarian reserve) is how many eggs remain in the ovaries.
- Egg quality refers to how likely those eggs are to result in a viable embryo.
Ovarian reserve is typically estimated using markers like anti-Müllerian hormone (AMH) levels and antral follicle count (AFC) seen on ultrasound. These help predict how the ovaries may respond to stimulation (or how many eggs might be retrieved in an IVF cycle).
However, these tests don’t tell us whether those eggs are chromosomally normal or capable of forming a healthy embryo.
It's also important to understand that quantity and quality don't always coincide. Someone can have a good number of eggs but still face challenges with embryo development, or a lower reserve but still achieve pregnancy. It's part of why so many people search for poor egg quality success stories, hoping to understand what's possible in their own situation. Outcomes can vary, and individual results don't always follow the expected pattern.
Why egg quality matters for fertility and miscarriage risk
Egg quality influences several processes in the journey to pregnancy:
- Fertilisation: Whether the egg and sperm successfully combine
- Embryo development: Whether the embryo grows and divides normally
- Implantation: Whether the embryo can attach to the uterine lining
- Chromosomal normality: Whether the embryo has the correct genetic makeup
If an egg has chromosomal abnormalities (for example, too many or too few chromosomes), it may not fertilise, may stop developing early, or may lead to miscarriage.
Chromosomal changes and age (a key driver)
Age is the most significant factor influencing egg quality. As eggs age, the likelihood of chromosomal errors tends to increase.
This happens because eggs remain in a resting state for many years before completing the final stages of cell division. Over time, the mechanisms that make chromosomes divide evenly can become less reliable.
The result is that, on average, older eggs are more likely to be chromosomally abnormal, which can affect embryo development and increase miscarriage risk.1
That said, age-related trends describe populations, not individuals. Many people conceive successfully at older ages, and a fertility specialist can help provide personalised context.
What influences egg quality (beyond age)
While age plays an important role, other factors may also influence egg quality. These are usually considered together, rather than in isolation.
Hormones and follicle environment
Eggs develop within follicles in the ovaries, supported by a hormonal environment. Hormones such as follicle-stimulating hormone (FSH) and luteinising hormone (LH) help guide growth and maturation.
Clinicians monitor hormone levels alongside ultrasound findings to understand how follicles are developing.
Health factors that can affect the egg environment
Certain health conditions may influence the environment in which eggs develop. These can include:
- Thyroid disorders
- Metabolic conditions such as insulin resistance
- Inflammatory conditions
In some cases, conditions like endometriosis or polycystic ovary syndrome (PCOS) may also affect how eggs mature or the ovarian environment.
Lifestyle exposures
Many people ask whether lifestyle changes can improve egg quality. Common areas of discussion include:
- Smoking
- Alcohol intake
- Recreational drug use
- Chronic stress
- Sleep patterns
Healthier habits can support overall reproductive health. However, it’s important to be realistic: lifestyle changes cannot guarantee improvements in egg quality. 2
If you’re considering changes, it’s best to discuss them with a clinician who can provide evidence-based guidance for your situation.
How egg quality is assessed in fertility care (and what can be inferred)
Because egg quality cannot be directly measured, clinicians use a combination of indicators before and during treatment. This is especially useful when patients are asking ‘can IVF be successful with poor egg quality?’ and want evidence-based guidance on what their results may mean.
Before IVF: what tests can and can’t tell you
Tests such as AMH and antral follicle count are valuable for estimating ovarian reserve. They help predict:
- How the ovaries may respond to stimulation
- How many eggs may be retrieved
However, they don’t predict whether those eggs will fertilise or develop into healthy embryos.
During IVF: maturity, fertilisation, and embryo development
IVF provides more insight into how eggs perform:
- Egg maturity: Whether eggs have reached the stage needed for fertilisation
- Fertilisation rates: How many eggs successfully combine with sperm
- Embryo development: How embryos grow over several days
It’s normal to see attrition at each step. Not every egg fertilises, and not every embryo develops. This is a reflection of natural biology rather than a sign that something has “gone wrong.”
Egg quality and IVF outcomes: what’s the relationship?
Egg quality plays a significant role in IVF outcomes because it influences embryo quality and the likelihood of having viable embryos for transfer.
However, it’s only one part of the picture. Outcomes also depend on:
- Sperm quality
- The uterine environment (endometrium)
- Laboratory conditions and techniques
- Chance
Embryo quality grading isn’t the same as genetic normality
In IVF, embryos are often graded based on how they look and develop (morphology). This helps embryologists select embryos with stronger development patterns.
However, morphology does not guarantee chromosomal normality. An embryo that looks “good” may still have genetic abnormalities, and vice versa.
Can egg quality be improved?
This is one of the most common and sensitive questions in fertility care.
Some factors can be optimised, such as overall health or correcting underlying conditions where clinically appropriate. Treatment protocols can also be used to support egg development.
However, there are no guaranteed “egg quality fixes.” Claims of quick improvements or miracle solutions should be approached with caution.
If you’re considering supplements or new interventions, it’s important to discuss them with your treating team.
What clinics can do: individualised protocols and timing
Fertility clinics can use treatment approaches to support the best possible outcomes. This may include:
- Adjusting stimulation protocols
- Timing egg retrieval carefully
- Choosing fertilisation methods (such as IVF or ICSI)
These decisions aim to maximise the chance of retrieving mature eggs and creating embryos, while recognising that outcomes cannot be guaranteed.
Supplements and add-ons: how to evaluate claims
If you’re exploring supplements or add-ons, it can help to ask:
- What evidence supports this?
- Who’s it intended for?
- What are the risks or side effects?
- What does it cost?
- Will it change clinical decision-making?
Options if egg quality is a concern
If egg quality becomes a challenge, there are several pathways that may be discussed. Each option depends on individual circumstances, and include:
- Trying sooner where possible
- IVF to maximise opportunities per cycle
- Embryo freezing strategies
- Donor eggs
There’s no single “right” path; the goal is to find an approach that aligns with your values, preferences, and clinical context.
When donor eggs may be discussed
Donor eggs may be considered when repeated cycles don’t result in viable embryos, or when age-related factors significantly affect outcomes.
This is a deeply personal decision that involves counselling, informed consent, and careful consideration of emotional, medical, and ethical factors.
Fertility preservation and planning
Egg freezing is an option for some people who wish to preserve fertility for the future, whether for medical or personal reasons. While it can be a useful planning tool, it doesn’t guarantee future pregnancy. Early discussion with a specialist can help you gain a better understanding of this procedure in the context of your specific circumstances.
Questions to ask your fertility specialist about egg quality
- What does my age, AMH, and AFC suggest about my expected response?
- What did my previous fertilisation or embryo development indicate?
- What changes would you consider in a future cycle, and why?
- Are there any additional tests worth doing before we proceed?
- What timelines would you recommend for my situation?
- When should we discuss donor options or alternative pathways?
FAQs
About the authors
Dr. Eashan Tambimuttu
Fertility Specialist MBBS, MRMed (Excellence), FRANZCOG AGES Accredited Surgeon
Dr Eashan Tambimuttu is a Fertility Specialist with expertise in minimally invasive surgery and reproductive medicine, trained at leading Australian hospitals.
View profileReferences
- Fertility Coalition. (n.d.). How age matters for your fertility. Your Fertility, Australian Government Department of Health. https://www.yourfertility.org.au/everyone/age
- Fertility Coalition. (n.d.). Lifestyle and health factors. Your Fertility, Australian Government Department of Health. https://www.yourfertility.org.au
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