How to improve egg quality: what science says about fertility after 35 and 40

For many women trying to conceive after the age of 35 or 40, one question quickly becomes central:

Can I improve my egg quality?

It is an understandable question. Female fertility gradually declines with age, and this decline becomes more pronounced during the mid-to-late 30s and 40s. However, fertility is complex, and age is only part of the picture.

Egg quality, ovarian reserve, hormonal health, lifestyle, sperm quality, embryo development and the condition of the uterus can all influence the chances of achieving a successful pregnancy.

Although there is no proven treatment that can simply “reverse” ovarian aging, understanding the factors associated with reproductive health can help women make informed decisions and prepare appropriately for natural conception or assisted reproductive treatments such as IVF.

What Does “Egg Quality” Actually Mean?

The term egg quality is widely used in fertility medicine, but it can sometimes be misunderstood.

Egg quality broadly refers to an oocyte’s biological and developmental potential: its ability to mature appropriately, be fertilized, support normal embryo development and ultimately contribute to a healthy pregnancy.

One particularly important component is chromosomal competence.

As women age, a greater proportion of their remaining eggs may contain chromosomal abnormalities. If an egg with an abnormal number of chromosomes is fertilized, the resulting embryo may fail to develop normally, fail to implant or result in miscarriage.

This is one of the principal reasons why fertility and IVF success rates generally decline with increasing female age.

Egg Quality vs Egg Quantity: They Are Not the Same

Understanding the difference between egg quality and ovarian reserve is essential.

Ovarian reserve describes primarily the quantity of remaining oocytes in the ovaries.

Tests such as Anti-Müllerian Hormone (AMH) and Antral Follicle Count (AFC) can help fertility specialists estimate ovarian reserve and predict how the ovaries may respond to stimulation during IVF.

They do not, however, directly measure egg quality.

This means that a woman can have a relatively reassuring AMH level but still experience age-related changes in egg quality. Conversely, a younger woman with low AMH may have fewer available eggs but should not automatically assume that those eggs are of poor quality.

For this reason, fertility specialists interpret ovarian reserve tests together with female age and the complete reproductive history.

Why Does Egg Quality Decline with Age?

Women are born with the pool of oocytes they will have during their reproductive lives.

Both the number and reproductive potential of those eggs decline over time.

Age-related cellular and molecular changes can affect the mechanisms responsible for normal chromosome division during egg maturation. As a result, chromosomal abnormalities become more common with advancing maternal age.

This is associated with a lower probability of conception and an increased risk of miscarriage.

The decline is gradual rather than something that suddenly happens on a woman’s 35th birthday. Nevertheless, the rate of reproductive decline becomes more significant during the later reproductive years.

What Happens to Fertility After 35?

Age 35 should not be viewed as a biological “cliff.”

Many women naturally conceive and have healthy pregnancies after 35.

However, fertility generally declines more rapidly from the mid-30s onward. This reflects changes in both the number of remaining eggs and their reproductive potential.

As a result, it may take longer to conceive, and the likelihood of miscarriage and chromosomal abnormalities increases with age.

This is why women aged 35 and older are generally advised not to wait as long before seeking a fertility evaluation if pregnancy is not occurring.

What About Egg Quality After 40?

After 40, age becomes an increasingly important consideration when planning fertility treatment.

Natural pregnancy is still possible, but the probability of conception per menstrual cycle is substantially lower than it is for younger women.

The same age-related biological changes can also influence IVF treatment. Even when eggs are successfully retrieved and fertilized, fewer embryos may have the chromosomal potential required to result in a successful pregnancy.

This does not mean that every woman over 40 has the same fertility prognosis.

Ovarian reserve, previous pregnancies, previous IVF response, general health, sperm factors and other clinical findings can substantially change the individual picture.

This is why personalized fertility assessment becomes especially important after 40.

Can You Really Improve Egg Quality?

This question requires a careful answer.

There is currently no established therapy capable of reliably reversing the biological aging of human eggs.

Therefore, claims that a particular food, supplement, IV treatment or regenerative therapy can “make old eggs young again” should be approached cautiously.

At the same time, reproductive health does not exist in isolation.

Nutrition, smoking, alcohol consumption, metabolic health, underlying medical conditions and exposure to oxidative stress can influence general health and potentially the biological environment in which follicles develop.

The practical objective is therefore not to promise that chronological ovarian aging can be reversed.

Instead, the goal is to optimize the woman’s overall reproductive health and treatment strategy while making appropriate use of the reproductive potential that remains.

Nutrition and Egg Quality

A balanced diet provides the micronutrients, proteins, healthy fats and other compounds required for normal cellular function.

For women preparing for pregnancy, nutritional adequacy is important for general and reproductive health.

Rather than searching for a single “fertility superfood,” it is more useful to focus on an overall high-quality dietary pattern containing vegetables, fruits, whole grains, appropriate protein sources and healthy fats.

Individual nutritional deficiencies may also need to be identified and corrected.

However, no particular diet has been proven to reverse age-related deterioration in egg quality.

Nutrition should therefore be considered part of preconception and fertility optimization, rather than a replacement for appropriate fertility assessment or treatment.

Antioxidants and Oxidative Stress

Oxidative stress occurs when the production of reactive molecules exceeds the body’s antioxidant defenses.

Because reproductive cells depend on tightly regulated cellular processes, researchers have investigated whether oxidative stress may contribute to reproductive aging and impaired reproductive function.

Antioxidants obtained through diet—and in selected circumstances through appropriately prescribed supplementation—may support normal cellular protection.

However, “more antioxidants” does not automatically mean “better fertility.”

Supplementation should ideally be based on individual needs and medical advice, particularly during fertility treatment.

Mitochondrial Health and the Oocyte

Mitochondria are responsible for producing much of the energy required by cells.

This is particularly relevant to oocytes, which require substantial energy during maturation, fertilization and early embryo development.

Mitochondrial function changes with reproductive aging, which has led to considerable scientific interest in the relationship between mitochondrial health and egg quality.

This is also one reason why metabolic health, adequate nutrition and oxidative balance have become important areas of research in reproductive medicine.

However, mitochondrial support should not be interpreted as a proven method for reversing reproductive aging.

Smoking and Egg Quality

If there is one lifestyle factor women trying to conceive should take particularly seriously, it is smoking.

Smoking is associated with adverse reproductive effects and should be avoided when preparing for pregnancy or fertility treatment.

Stopping smoking also provides substantial benefits for cardiovascular, respiratory and overall health.

Exposure to recreational drugs should likewise be avoided, while alcohol and caffeine intake should be discussed with the woman’s healthcare team when planning pregnancy.

Weight, Metabolic Health and Fertility

Both undernutrition and significant excess weight can influence reproductive and metabolic health.

Insulin resistance, metabolic disorders and some endocrine conditions may affect ovulation, hormonal regulation and reproductive outcomes.

The objective should not be rapid weight loss before IVF.

Instead, where appropriate, achieving a sustainable and medically suitable weight while improving metabolic health can form part of a broader preconception strategy.

Each woman’s circumstances are different, so nutritional and metabolic recommendations should be individualized.

Sleep, Exercise and Stress

Regular physical activity, adequate sleep and stress management are valuable components of general health.

Moderate exercise can support cardiovascular and metabolic health and may form part of a healthy preconception lifestyle.

Sleep is also important for multiple physiological processes, including endocrine and metabolic regulation.

Stress itself should not be presented as the reason a woman has difficulty conceiving. Fertility treatment can be emotionally demanding, however, and psychological support, appropriate rest and stress-management strategies may improve overall wellbeing during the process.

What About Fertility Supplements?

The fertility supplement market is extensive, and women are frequently exposed to claims that particular combinations can dramatically improve egg quality.

Several vitamins, minerals and antioxidant compounds have been studied in reproductive medicine.

However, evidence varies considerably according to the supplement, patient population and outcome being measured.

A supplement should not be assumed to be beneficial simply because it is marketed as “natural.”

Before beginning a fertility supplement program—particularly during IVF—it is sensible to discuss the ingredients, doses and possible interactions with a fertility specialist.

The aim should be targeted nutritional support where appropriate, rather than taking large combinations of supplements without individualized assessment.

Can Fertility IV Therapy Help?

Intravenous vitamin and nutrient therapy is increasingly being offered as an adjunct to fertility preparation.

A personalized fertility IV protocol may provide selected vitamins, minerals, amino acids, antioxidants and other nutrients directly through intravenous administration.

At Chania Fertility Unit, Ovarian Boost IV Therapy is used as part of an individualized preparation strategy for selected patients, including women undergoing ovarian rejuvenation procedures.

The objective is to support nutritional adequacy, antioxidant defenses, metabolic and mitochondrial function and the broader biological environment before treatment.

However, IV nutrient therapy should be considered a supportive intervention. It cannot be claimed to reverse ovarian aging, create new eggs or guarantee improved egg quality or pregnancy.

Preparing for IVF After 35 or 40

Women preparing for IVF after 35 or 40 often benefit from looking at fertility preparation as a complete strategy rather than focusing exclusively on one laboratory result or supplement.

A comprehensive assessment may include:

• Age and reproductive history
• AMH and other reproductive hormones
• Antral Follicle Count (AFC)
• Previous response to ovarian stimulation
• General and metabolic health
• Nutritional status
• Uterine and endometrial assessment
• Partner’s semen analysis and, when indicated, additional male fertility evaluation

The results can then be used to design an individualized IVF strategy.

For women in their late 30s or 40s, time is particularly important. Spending many months attempting unproven methods to improve egg quality before obtaining specialist advice may ultimately reduce rather than increase reproductive options.

Can Ovarian Rejuvenation Improve Egg Quality?

Ovarian rejuvenation is an emerging area of regenerative reproductive medicine.

Approaches being investigated include Platelet-Rich Plasma (PRP), Enriched PRP, exosome-based therapies and stem-cell-related regenerative techniques.

The biological rationale behind these approaches includes investigation of growth factors, cellular signaling, tissue repair, vascularization and the ovarian microenvironment.

These techniques are of particular research interest for women with diminished ovarian reserve, poor ovarian response and age-related decline in ovarian function.

However, an important distinction must be made.

Regenerative fertility therapies are not established methods for reversing the biological age of an egg, and they cannot guarantee increased egg quality, restoration of ovarian reserve, successful IVF or pregnancy.

Patients considering these approaches should therefore receive individualized counseling about their reproductive circumstances, potential benefits, uncertainties and available alternatives.

When Should You See a Fertility Specialist?

If you are concerned about egg quality or age-related fertility decline, timing matters.

Women under 35 are commonly advised to seek fertility evaluation after 12 months of regular unprotected intercourse without pregnancy.

For women 35 or older, evaluation is generally recommended after approximately six months without conception.

For women over 40, earlier assessment may be appropriate rather than waiting for six or twelve months.

Earlier evaluation may also be appropriate at any age when there are known fertility concerns, such as irregular periods, endometriosis, previous ovarian surgery, diminished ovarian reserve or a history of unsuccessful fertility treatment.

Egg Quality After 35 and 40: Focus on What You Can Control

You cannot change your chronological age.

And currently, no treatment can reliably turn an older egg into a younger one.

But this does not mean there is nothing you can do.

Understanding your ovarian reserve, addressing modifiable health factors, maintaining appropriate nutrition, avoiding smoking, investigating both female and male fertility factors and obtaining timely specialist advice can help create a more informed and personalized fertility strategy.

For women considering IVF, the objective should be to make the best possible use of the reproductive potential available now, rather than lose valuable time pursuing unrealistic promises of reversing reproductive aging.

At Chania Fertility Unit, fertility preparation can be individualized according to a woman’s age, ovarian reserve, previous treatment history, nutritional and metabolic profile and reproductive goals. Conventional assisted reproduction can also be integrated, where appropriate, with supportive and emerging regenerative fertility approaches as part of a personalized treatment plan.