Preparing for Conception or IVF: A Book We Recommend

Patients preparing for conception or fertility treatment often ask what they can do in the weeks and months before beginning their journey. While there is an enormous amount of fertility information online, it can be difficult to distinguish practical, evidence-informed guidance from unsupported claims or one-size-fits-all advice.

At Pedieos IVF Center, we believe that well-informed patients are better equipped to participate in conversations about their care. For this reason, we would like to introduce The Egg & Sperm Quality Plan: A Science-Backed 90-Day Roadmap for Natural Conception and IVF Success, written by fertility specialist Dr Vasileios Sarafis.

The book is designed to help individuals and couples understand the period before natural conception, IUI or IVF and approach it with greater clarity and structure.

A structured approach for both partners

One of the book’s central themes is that fertility preparation should involve both partners. Rather than focusing exclusively on egg quality, it also considers sperm health and the contribution that both individuals make to conception and embryo development.

The book presents a structured 90-day framework covering areas such as nutrition, sleep, stress management, metabolic health, supplements and environmental factors. It also discusses the biological development of eggs and sperm during the months before conception.

This does not mean that every fertility outcome can be changed through lifestyle choices. Many causes of infertility require specialist investigation and medical treatment. However, understanding the preconception period may help patients make informed decisions, develop sustainable habits and prepare more confidently for the next stage of care.

“The medical treatment we use to stimulate the ovaries depend on hormones that promote egg production and maturation. However, a lot of other things help the final success of an IVF treatment. This book is a great source of information on all “supplementary” agents that significantly promote the final success, which is a healthy live birth.” – Dr. Krinos Trokoudes – Medical Director, Endocrinologist & Reproductive Medical Specialist

What readers will find inside

The book combines fertility education with practical tools intended to help readers organise their preparation.

Topics include:

    • A 12-week fertility-preparation roadmap with weekly checklist
    • Egg quality, sperm health and sperm DNA integrity
    • Nutrition and evidence-informed supplement guidance
    • Fertility considerations for patients over 40
    • PCOS, endometriosis and male-factor infertility
    • Understanding fertility investigations and diagnostic tests
    • Questions to consider when choosing an IVF clinic
    • Emotional resilience during treatment and after setbacks
    • Trackers, planners and questions to discuss with a fertility specialist

The book also includes a foreword by reproductive medicine specialist Dr Luca Gianaroli.

Information without unrealistic promises

Fertility treatment can be emotionally demanding, and patients are often exposed to advice promising dramatic improvements or guaranteed results. No book, supplement, diet or lifestyle programme can guarantee natural conception or IVF success.

A responsible fertility resource should help readers understand the available evidence while also recognising its limitations. Recommendations that may be suitable for one person may be unnecessary or occasionally unsuitable for another.

Supplements, significant dietary changes and decisions about fertility testing should therefore be discussed with a qualified healthcare professional, particularly when a patient has an existing medical condition or is already receiving treatment.

A recommended resource from Pedieos IVF Center

At Pedieos IVF Center, our role is to provide personalised fertility care based on each patient’s medical history, diagnosis and individual circumstances. We are recommending this book because it offers readers a structured introduction to fertility preparation while encouraging both partners to become informed participants in the process.

Readers interested in exploring the book can find the paperback and available editions through Amazon.

Get your copy of the book on Amazaon →

VIEW ON AMAZON

Written by Dr Vasileios Sarafis, a UK-trained Consultant Obstetrician, Gynaecologist and Fertility Specialist, the book draws on his clinical experience and training at C.Re.A.Te Fertility under Professors Geeta Nargund and Stuart Campbell.

This article is for general educational purposes and does not replace individual medical advice, diagnosis or treatment. Always discuss supplements, lifestyle changes and fertility decisions with your healthcare provider.

Genetic Screening in Egg Donation: What Patients Should Know

Genetic screening is an important part of responsible egg donation, helping fertility specialists identify and manage the risk of certain inherited conditions. However, as screening panels become increasingly extensive, an important question arises: how much genetic testing is appropriate?

A new review prepared by Aphrodite Egg Bank, the in-house egg bank of Pedieos IVF Center, presents both sides of the expanded carrier screening debate. Broader screening may provide useful information and support donor-recipient genetic matching. At the same time, it can uncover unexpected findings, create additional costs, affect donor privacy and sometimes cause healthy donors to be excluded unnecessarily.

It is also important to understand that no genetic test can eliminate every possible risk or guarantee the health of a future child. Results must therefore be interpreted carefully, with appropriate professional guidance and a clear understanding of what the screening can—and cannot—show.

At Pedieos IVF Center, we support an individualised and informed approach, taking into account each patient’s circumstances, medical history and treatment needs.

Read the full publication and Aphrodite Egg Bank’s position. →

READ RESEARCH REPORT

New Research on Vitrified Donor Egg Outcomes

Aphrodite Egg Bank, the in-house egg bank of Pedieos IVF Center, has published a new two-centre evaluation of clinical outcomes using vitrified donor oocytes.

The report follows two experienced fertility centres and examines how laboratory familiarity with the warming and handling of vitrified oocytes can influence post-thaw survival and treatment outcomes. The results show a clear learning curve: as the laboratory teams gained experience, oocyte survival improved and subsequently stabilised at consistently high levels.

Across the two centres, fertilisation rates reached 76.2% and 81%, while positive pregnancy rates following fresh embryo transfer were 56.7% and 58%. The findings demonstrate the importance of combining high-quality donor oocytes with trained embryologists, carefully controlled laboratory procedures and consistent monitoring.

For patients considering IVF with donor eggs, the report offers encouraging evidence about the effectiveness of modern oocyte vitrification. It also underlines why the experience of both the egg bank and the treating fertility centre remains an essential part of the treatment journey.

Read the full clinical research report →

READ RESEARCH REPORT

How Many Eggs Are Needed to Achieve One Blastocyst in IVF?

A common question in IVF is: “How many eggs are needed to obtain at least one blastocyst?” Understanding this requires knowing what blastocysts and MII oocytes are, as well as how age and other patient factors affect embryo development.

What Is a Blastocyst?

A blastocyst is an embryo that has reached the 5–6 day stage of development after fertilization. At this point, the embryo has differentiated into an outer layer of cells called the trophectoderm, which will form the placenta, and an inner cell mass that will develop into the fetus. Blastocysts are preferred for transfer because they have a higher implantation potential and better chances of leading to a successful pregnancy compared to earlier-stage embryos.

What Are MII Oocytes?

MII (Metaphase II) oocytes are mature eggs ready for fertilization. Only mature oocytes can develop into embryos, and their quality directly impacts the likelihood of reaching the blastocyst stage. In IVF, the number and quality of MII oocytes retrieved are critical factors in predicting success.

Insights from Research

This study analyzed over 2,600 IVF cycles that included preimplantation genetic testing for aneuploidy (PGT-A). The researchers created a predictive model to determine how many mature oocytes are required to obtain at least one euploid blastocyst. The model shows that:

  • Younger women generally require fewer MII oocytes.
  • Older women require more MII oocytes due to higher rates of chromosomal abnormalities.
Study 1: Predictive Model for Euploid Blastocysts (Fertility and Sterility, 2025)

Figure1: Graphic representation of the model. The x axis shows the number of MII oocytes and the y axis shows the probability of having at least one euploid blastocyst (pEB). Each line represents maternal age in years. Figure adjusted from Rodríguez-Varela et al., 2025.

This study provides a practical, individualized estimate for clinicians: by knowing a patient’s age and number of retrieved MII oocytes, the probability of achieving at least one euploid blastocyst can be predicted, which helps in planning IVF cycles more effectively.

Study 2: Age-Based Thresholds for MII Oocytes (World Scientific, 2025)

The second study established general thresholds for the number of MII oocytes needed to achieve at least one euploid blastocyst. Key findings include: – Women under 36 typically need around 6–7 MII oocytes. – Older women require progressively more eggs to reach a similar probability of success.

Figure 2: Estimated number of MII oocytes required to obtain at least on euploid blastocyst according to maternal age. Figure adjusted from Nakagawa et al., 2024.

Key Insight: These thresholds provide practical guidance to help patients understand their chances and plan IVF cycles. They also highlight that options such as donor eggs are always available when needed to improve the likelihood of success.

Additional Considerations

While age is a major determinant of how many MII oocytes are needed, other factors also play important roles. These include body mass index (BMI), ovarian reserve markers, lifestyle factors such as smoking or alcohol use, underlying medical conditions, and previous ovarian response to stimulation. All of these variables can influence egg quality and blastocyst formation, making individualized assessment essential for accurate predictions.

Overall Takeaways

  • For younger women, approximately 6–7 MII oocytes often yield at least one euploid blastocyst.
  • Older women may need 10 or more MII oocytes due to declining egg quality
  • The number of eggs required increases exponentially after the age of 40.
  • Predictive models and age-based thresholds help clinicians make data-driven decisions for IVF cycles, improving success rates and managing patient expectations.
  • Individual factors such as BMI, ovarian reserve, lifestyle, and medical history should also be considered when estimating the number of eggs required.
  • These models are designed to inform and guide patients, not to create stress or discouragement
  • Options like donor eggs remain available if needed.

References:
Nakagawa, K., Horikawa, T., Watanabe, H., Shirai, A., Kataoka, H., Takamizawa, S., Maruyama, T., Kuroda, K. and Sugiyama, R., 2025. Estimating the Number of Retrieved Oocytes Needed to Obtain at Least One Euploid Blastocyst. Fertility & Reproduction, 7(03), pp.122-128.
Rodríguez-Varela, C., Mascarós, J.M., Labarta, E., Silla, N. and Bosch, E., 2024. Minimum number of mature oocytes needed to obtain at least one euploid blastocyst according to female age in in vitro fertilization treatment cycles. Fertility and Sterility, 122(4), pp.658-666.

Does Freezing and Thawing Oocytes Affect Embryo Quality and IVF Success Rates?

If you are considering freezing your own eggs or using previously frozen oocytes for IVF, it’s normal to wonder whether freezing might reduce egg quality or affect your chances of success. Many patients imagine frozen eggs are somehow “weaker” than fresh ones. The truth is reassuring, with modern techniques, frozen eggs are just as capable as fresh ones, if they survive the thaw.

How Egg Freezing Works Today

Egg freezing has evolved dramatically over the last decade. At Pedieos IVF Centre, we use vitrification with Kitazato systems, a rapid-freezing method that prevents ice crystals from forming inside the egg.

Why is this important?

  • Older slow-freezing methods often allowed tiny ice crystals to form, which could damage delicate internal structures.
  • Vitrification cools eggs so quickly that they turn into a glass-like state, preserving their structure and function.

Think of it as putting your eggs on pause: their biological age and quality are frozen in time until they’re needed, giving you control over when to use them.

What Happens During Thawing

When vitrified eggs are warmed, the majority survive and retain their internal structures. A thawed egg is biologically very similar to a fresh one, and its potential for fertilisation remains intact.

Here’s what happens in the lab:

  • Most eggs survive the warming process
  • Cellular structures remain stable
  • The egg can be fertilised normally

From a laboratory perspective, a successfully thawed egg behaves just like a fresh egg. The freezing process itself does not reduce its ability to develop into a healthy embryo.

Fertilisation and Embryo Development

Once thawed, eggs are fertilised and develop into embryos in the same way as fresh eggs.

Research and clinical experience show that embryos from frozen–thawed eggs:

  • Fertilise normally
  • Progress through early developmental stages at expected rates
  • Reach the blastocyst stage
  • Can form good-quality embryos suitable for transfer or freezing

In other words, freezing does not prevent an egg from becoming a healthy embryo.

Factors That Influence IVF Success

While freezing itself does not harm eggs, IVF outcomes depend on factors present before freezing:

  • Age at freezing: Younger eggs are generally higher quality.
  • Egg quality at freezing: Reflects ovarian health at that time.
  • Embryo development: Not every egg will fertilise or develop, even when fresh.
  • Uterine receptivity: The environment where the embryo implants matters.

The most important point: it’s the age and quality of the egg at the time of freezing, not the freezing process, that determines future success. Freezing preserves eggs at that moment, effectively “pausing” their biological clock.

Why Freezing Eggs Can Be Empowering

Egg freezing is more than just a lab procedure, it’s a fertility preservation tool that offers women flexibility, control, and reassurance. Some choose it for medical reasons, such as before chemotherapy, radiation, or surgeries that could affect fertility. Preserving eggs beforehand gives these patients the chance to have children later, even if their natural fertility is impacted.

Others choose egg freezing for personal or lifestyle reasons, allowing them to plan family-building on their own timeline. It’s increasingly common for women in their late 20s or early 30s to preserve eggs proactively, before natural age-related decline begins.

In all cases, egg freezing helps women safeguard their fertility for the future, offering flexibility in timing, preservation of biologically younger eggs, and peace of mind that their options remain open.

Fun Fact

One of the longest-frozen human oocytes used to achieve a healthy pregnancy had been stored for over 14 years. This demonstrates how effective modern vitrification is, eggs can remain biologically “young” for many years until you’re ready to use them.

Key Takeaway

Freezing and thawing oocytes using modern vitrification techniques does not compromise embryo quality or IVF success. What matters most is the age and quality of the egg at the time it was frozen, not the freezing process itself.

At Pedieos IVF Centre, we use the latest vitrification technology to ensure that your eggs are preserved safely, giving you confidence and flexibility in your fertility journey.

Recurrent Implantation Failure: Causes & Advanced Treatment Options

recurrent implantation failure in IVF

Recurrent implantation failure is one of the most emotionally exhausting experiences in fertility treatment. After multiple IVF cycles, good-quality embryos, and careful medical supervision, the absence of implantation can feel both confusing and devastating.

Yet implantation is not a simple event. It is a highly coordinated biological dialogue between embryo and endometrium. When that dialogue fails repeatedly, it signals that something deeper requires investigation.

Understanding the underlying mechanisms behind recurrent implantation failure allows us to move beyond repeated IVF failure and toward personalized, evidence-based solutions.

woman concerned due to failed ivf

What Is Recurrent Implantation Failure?

There is no single universal definition, but recurrent implantation failure (RIF) is commonly described as the failure to achieve pregnancy after transferring good-quality embryos across multiple IVF cycles — typically two to three transfers.

Importantly, implantation failure is not always caused by poor embryos. Many patients with RIF have excellent blastocysts. The issue often lies in the interaction between embryo and uterus rather than embryo quality alone.

Implantation depends on precise timing, hormonal synchronization, immune tolerance, and adequate endometrial development. A disturbance in any of these systems may lead to repeated IVF failure.

doctor support

Why Implantation Is So Biologically Complex

Implantation occurs during a narrow time window known as the “window of implantation.” During this period, the uterine lining becomes temporarily receptive, expressing specific molecules that allow embryo attachment.

At the same time, the embryo must be chromosomally normal and capable of signaling its presence. The immune system must tolerate the embryo rather than recognize it as foreign. Blood flow to the uterus must be sufficient to sustain early placental development.

When recurrent implantation failure occurs, we are often observing disruption in one — or several — of these coordinated processes.

the root cause of recurrent implantation failure

The Main Causes of Recurrent Implantation Failure

Rather than a single defect, RIF is usually multifactorial. Below are the most clinically significant contributors.

Embryo Genetic Abnormalities

Even visually “perfect” embryos may carry chromosomal errors. As maternal age increases, the rate of aneuploidy rises significantly. These chromosomal abnormalities frequently prevent implantation altogether, rather than causing miscarriage.

This explains why patients may experience repeated IVF failure despite high-grade embryos.

Preimplantation Genetic Testing (PGT-A) can identify chromosomally normal embryos before transfer. While it does not solve uterine-related causes, it reduces embryo-related implantation failure and can shorten time to pregnancy in selected patients.

Thin Endometrial Lining (Thin Lining IVF)

One of the most challenging implantation failure causes is inadequate endometrial development.

For successful implantation, the endometrium must not only reach sufficient thickness — typically above 7 mm — but also develop proper structure, blood flow, and hormonal responsiveness.

In thin lining IVF cases, even if embryos are genetically normal, the uterine environment may not be biologically prepared to support implantation.

Thin endometrium may result from previous uterine surgeries, infections, aggressive curettage procedures, hormonal resistance, or impaired uterine blood flow. Sometimes the cause is unclear.

Management requires individualized adjustment of estrogen protocols, evaluation for chronic inflammation, and in selected cases, regenerative approaches such as platelet-rich plasma (PRP) therapy. Improving uterine perfusion and correcting underlying pathology often significantly enhances implantation potential.

Uterine Structural Abnormalities

The physical environment of the uterus must allow uninterrupted embryo attachment. Even small structural irregularities can interfere with this delicate process.

Submucosal fibroids, uterine polyps, adhesions (Asherman’s syndrome), septa, or adenomyosis may disrupt the architecture of the endometrial cavity.

Many of these abnormalities are subtle and may not be visible on basic ultrasound. Advanced imaging techniques or diagnostic hysteroscopy are often necessary in patients with recurrent implantation failure.

When structural problems are corrected surgically, implantation rates frequently improve — particularly in younger patients with otherwise good prognosis.

Chronic Endometritis: The Silent Disruptor

Chronic endometritis is a low-grade inflammatory condition of the uterine lining that often presents without symptoms. It does not typically cause pain or abnormal bleeding, making it easy to overlook.

However, persistent inflammation alters endometrial receptivity and may significantly contribute to repeated IVF failure.

Diagnosis requires endometrial biopsy and immunohistochemical testing (such as CD138 staining). When identified, targeted antibiotic therapy can restore normal uterine conditions and improve implantation outcomes.

In many RIF cases, this treatable condition is only discovered after specialized evaluation.

Immune and Inflammatory Factors

Implantation requires immune tolerance. The embryo carries genetic material from both parents, meaning the maternal immune system must adapt rather than reject it.

In some women, abnormal immune activation — including elevated natural killer (NK) cell activity or autoimmune disorders — may interfere with implantation.

The role of immune testing in recurrent implantation failure remains debated, but in selected patients with autoimmune history or unexplained repeated IVF failure, immune modulation strategies may be considered.

These can include low-dose aspirin, heparin, corticosteroids, or intralipid therapy. Such interventions should always be individualized and carefully supervised.

Hormonal Timing and the Window of Implantation

Even when embryos are chromosomally normal and the uterus appears structurally normal, implantation can fail if hormonal synchronization is slightly misaligned.

Progesterone exposure must occur for a precise duration before embryo transfer. In some women, the window of implantation is displaced, meaning the embryo is transferred either too early or too late.

Endometrial Receptivity Analysis (ERA) aims to identify this personalized window. Although not necessary for all IVF patients, it may provide clarity in cases of unexplained recurrent implantation failure.

IVF lab

Advanced Treatment Approaches

The management of recurrent implantation failure has evolved significantly over the past decade. Instead of repeating identical IVF protocols, modern reproductive medicine focuses on personalization.

This may involve:

  • Genetic testing of embryos (PGT-A)
  • Adjusted hormonal preparation protocols
  • Investigation and treatment of thin lining IVF cases
  • Hysteroscopic correction of structural issues
  • Targeted treatment of chronic endometritis
  • Personalized embryo transfer timing

The goal is not simply to try again — but to try differently, guided by investigation.

doctor holding hand

Emotional and Clinical Perspective

Repeated IVF failure is not only a medical condition; it is a profound emotional burden. Patients often question their bodies, their decisions, and their chances of success.

However, recurrent implantation failure does not mean pregnancy is impossible. It means deeper evaluation is necessary.

With systematic investigation and individualized care, many patients who initially experienced repeated IVF failure ultimately achieve successful pregnancies.

Coupole speaking to a doctor about recurrent implantation failure

When to Seek Specialized Evaluation

A thorough recurrent implantation failure assessment should be considered after:

  • Two or more failed transfers of high-quality embryos
  • Persistent thin lining IVF cycles
  • Unexplained implantation failure despite good prognosis
  • Repeated biochemical pregnancies

Early investigation prevents repeated unsuccessful cycles and helps shift from trial-and-error to targeted treatment.

Final Thoughts

Recurrent implantation failure is complex and multifactorial. It rarely has a single cause and almost never benefits from repeating the same protocol without investigation.

Whether the issue lies in embryo genetics, thin endometrial lining, subtle inflammation, structural abnormalities, or timing discrepancies, modern fertility medicine offers advanced diagnostic tools and personalized therapeutic strategies.

Repeated IVF failure is not the end of the journey — it is an indication to look deeper, refine the approach, and move forward with clarity.

IVF After 40: What Really Improves Success Rates?

IVF after 40 success

Many women today begin or expand their families later in life. While pregnancy after 40 is absolutely possible, fertility naturally declines with age, and this directly affects IVF after 40 success rates.

However, age alone does not tell the full story. The outcome of IVF over 40 depends on several biological factors, treatment strategies, and individualized medical decisions.

In this guide, we explore what truly influences IVF success after 40 — and what can meaningfully improve your chances.

Fertility when over 40

Why Fertility Declines After 40

Female fertility declines gradually in the 30s and more significantly after 40. The main reason is not simply the number of eggs remaining, but their quality.

As women age:

  • The number of eggs decreases (lower ovarian reserve)
  • The proportion of genetically normal eggs declines
  • The risk of chromosomal abnormalities increases

This change in egg quality explains why miscarriage rates also rise after 40.

When discussing IVF over 40, it is important to understand that IVF cannot reverse biological aging. What it can do is optimize the conditions under which fertilization and embryo development occur.

IVF success rates over 40

What Are Realistic IVF Success Rates After 40?

Success rates vary depending on several factors, including whether a woman uses her own eggs or donor eggs.

With a woman’s own eggs:

  • IVF at 40 may still be reasonable depending on ovarian reserve
  • IVF at 42 typically shows lower implantation rates
  • Pregnancy at 43 IVF is possible, but the chances decrease significantly

The main limiting factor is embryo chromosomal normality. As maternal age increases, the percentage of embryos that are chromosomally normal declines.

That said, statistics reflect population averages. Individual outcomes can differ significantly depending on overall reproductive health.

The Most Important Factors That Influence IVF After 40

1. Egg Quality

Egg quality is the single most influential factor in IVF after 40 success rates.

Even when multiple eggs are retrieved, not all will develop into viable embryos. The proportion of genetically normal embryos decreases with age, which affects implantation and live birth rates.

Testing embryo chromosomal health through preimplantation genetic testing (PGT) can help identify embryos with normal chromosomal patterns, potentially improving implantation success.

2. Ovarian Reserve

Ovarian reserve refers to the number of eggs remaining in the ovaries. This is commonly assessed using:

  • AMH (anti-Müllerian hormone)
  • Antral follicle count via ultrasound

A woman aged 41 with good ovarian reserve may respond better to stimulation than a woman aged 38 with very low reserve.

Age is important, but ovarian biology varies between individuals.

3. Embryo Selection and Laboratory Quality

Advanced embryology techniques can influence outcomes.

Modern IVF laboratories may use:

  • Time-lapse embryo monitoring
  • Optimized culture environments
  • Genetic testing for chromosomal abnormalities

These technologies do not change egg age but can improve embryo selection precision.

4. Uterine Health

Implantation depends not only on the embryo but also on the uterine environment.

Conditions that may affect implantation include:

  • Fibroids
  • Polyps
  • Adenomyosis
  • Thin endometrium

Proper uterine evaluation is especially important in IVF at 42 or older, when each embryo transfer carries increased significance.

5. Lifestyle and Metabolic Health

While lifestyle cannot reverse age-related egg decline, overall metabolic health still plays a role.

Optimizing:

  • Body weight
  • Thyroid function
  • Vitamin D levels
  • Blood sugar balance

can support better hormonal regulation and implantation conditions.

Couple consulting a doctor

IVF at 42 or 43: Is It Still Worth Trying?

This is one of the most common and emotional questions patients ask.

Pregnancy at 43 IVF using one’s own eggs is possible, but success rates are typically lower compared to younger age groups.

Some women may choose to attempt IVF with their own eggs first. Others may consider donor egg IVF, which significantly increases success rates because egg quality reflects the donor’s age rather than the recipient’s age.

The right decision depends on:

  • Ovarian reserve
  • Personal preferences
  • Emotional readiness
  • Medical evaluation

Individual counseling is essential in this age group.

Does PGT Improve IVF Success After 40?

Preimplantation genetic testing (PGT-A) screens embryos for chromosomal abnormalities before transfer.

Because chromosomal abnormalities increase after 40, PGT can:

  • Reduce miscarriage risk
  • Improve selection of viable embryos
  • Avoid transferring embryos unlikely to implant

However, PGT does not increase the number of normal embryos — it helps identify them.

Its usefulness depends on how many embryos are available for testing.

IVF with Egg Donor

When Should Donor Eggs Be Considered?

For women with:

  • Very low ovarian reserve
  • Repeated IVF failure
  • Recurrent chromosomal abnormalities

Donor egg IVF may offer significantly higher success rates.

This is because embryo quality reflects the donor’s age, not the recipient’s age.

For some women, donor IVF provides a more predictable path to pregnancy after 42 or 43.

Emotional Considerations After 40

Fertility treatment after 40 is often emotionally complex.

Women may feel:

  • Time pressure
  • Anxiety about declining success
  • Confusion about treatment choices

Clear medical guidance and realistic counseling are crucial. Success is not determined by age alone, but by careful evaluation and individualized planning.

Key Takeaways

  • IVF after 40 success rates depend primarily on egg quality.
  • Ovarian reserve and embryo genetics strongly influence outcomes.
  • IVF at 42 or 43 is possible, but success varies significantly.
  • PGT may improve embryo selection.
  • Donor egg IVF can substantially increase pregnancy rates when appropriate.

Age is a factor — but it is not the only factor. With thorough evaluation and tailored treatment strategies, many women over 40 achieve successful pregnancies.

What Is the Optimal Endometrial Thickness for Implantation?

What Is the Endometrium and Why Is It Important?

The endometrium is the tissue where an embryo implants and develops into a pregnancy. Throughout the menstrual cycle, it responds to estrogen and progesterone by thickening, changing structure, and becoming receptive during a short period known as the window of implantation.

For implantation to succeed, the endometrium must be:

  • Thick enough to support an implanting embryo
  • Properly developed and hormonally synchronized
  • Receptive at the correct time

Thickness is easy to measure by ultrasound, which is why it is often used as a marker of uterine readiness.

What Is Considered an “Optimal” Endometrial Thickness?

Traditionally, clinical practice has suggested:

  • <6 mm → thin endometrium, lower implantation rates
  • 7–8 mm → minimum threshold associated with better outcomes
  • 8–12 mm → commonly considered optimal

What Does Large-Scale Research Show?

A major study published in July 2024 analysed data from the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System (SART CORS), including 244,001 embryo transfer cycles. This makes it one of the largest studies ever conducted on endometrial thickness and live birth rates.


Key findings from the abstract and analysis include:

  • Live birth rates increase steadily as endometrial thickness rises up to around 8 mm
  • Beyond 8–10 mm, live birth rates plateau
  • Importantly, very thick endometria did not show a significant decline in live birth rates

The accompanying figure illustrates this clearly: the probability of live birth rises sharply with increasing thickness up to approximately 8 mm, after which the curve flattens. This suggests that reaching a minimum receptive threshold is critical but exceeding it offers little additional benefit.

Figure 1: The diagram demonstrates how the increase in endometrial thickness corresponds to an increase in the probability of a life birth. Diagram adjusted from Schmiech, K. et al. 2024

What Causes a Thin Endometrium?

A thin endometrium can result from:

  • Low estrogen exposure
  • Previous uterine surgery or repeated curettage
  • Inflammation or infection
  • Reduced uterine blood flow
  • Intrauterine adhesions (Asherman’s syndrome)

Identifying the underlying cause is crucial for targeted management.

The Bottom Line

So, how thick should the endometrium be to increase the chances of embryo implantation and live birth?

  • The most important threshold appears to be around 8 mm
  • Live birth rates improve significantly up to 8 mm
  • Beyond 8 mm of thickness, the success rate remains relatively constant
  • Endometrial receptivity, timing, and overall uterine health are just as important as thickness

Large-scale data now reassure both patients and clinicians that success is not about achieving the thickest lining possible, but about creating the right environment at the right time.

Reference: Schmiech, K., Li, M., Chen, L. X., Dow, M., & Baker, V. L. (2024). IMPACT OF ENDOMETRIAL THICKNESS ON LIVE BIRTH RATE, A STUDY UTILIZING THE SOCIETY FOR ASSISTED REPRODUCTIVE TECHONOLOGY CLINICAL OUTCOMES REPORTING SYSTEM (SART CORS). Fertility and Sterility, 122(1), e6-e7.

Does My Age Matter When Using Donor Eggs in IVF?

Using donor eggs is one of the most effective treatment options in IVF, particularly for women whose own egg quality has declined due to age or other factors. A common and very understandable question is: If the eggs come from a young donor, does the recipient’s age still matter?

The answer is yes – but in a different way than many patients expect.

The Donor’s Age: The Main Driver of Embryo Quality

When donor eggs are used, the donor’s age is the primary factor determining embryo quality. Egg donors are young and carefully screened, which means their oocytes are far more likely to be healthy and chromosomally normal.

This is why IVF success rates with donor eggs are generally high and relatively consistent—even for women in their 40s or early 50s. By using young donor oocytes, we largely overcome the age-related decline in egg quality that naturally occurs over time.

In short: Embryo quality depends mainly on the donor, not the recipient.

Why Recipient Age Still Matters

Although embryo quality is determined by the donor, implantation and pregnancy occur in the recipient’s body. For this reason, the recipient’s age can still influence outcomes.

As women age, changes may occur in:

  • Uterine health
  • Endometrial receptivity (how well the uterine lining allows implantation)
  • Blood flow to the uterus
  • Hormonal responsiveness
  • General medical condition

These factors can affect whether a high-quality embryo implants successfully and whether the pregnancy continues to a live birth.

What the Evidence Shows

Does My Age Matter When Using Donor Eggs in IVF 3
Does My Age Matter When Using Donor Eggs in IVF 4
Does My Age Matter When Using Donor Eggs in IVF 5

Figure 1. Effect of recipient age on IVF outcomes using donor oocytes. Panel A shows live birth rates by recipient age, demonstrating a gradual decline with increasing age. Panel B shows pregnancy loss rates, which increase as recipient age advances. Panel C shows implantation failure rates, which also rise with age. These findings indicate that while donor oocytes largely overcome age-related declines in egg quality, recipient age may still influence implantation and pregnancy continuation. (Figure adjusted from Sebastian-Leon et al., 2025)

Research demonstrates that live birth rates with donor eggs remain high across most age groups. However, there is a gradual shift in outcomes as recipient age increases.

The graph illustrates that after the age of 40, there is a steady decrease in success rates and an increase in implantation failures and pregnancy losses.

More specifically:

  • Live birth rates decline gradually with increasing recipient age.
  • Pregnancy loss rates rise as age advances.
  • Implantation failure becomes more frequent in older recipients.

These findings indicate that while donor oocytes largely overcome age-related declines in egg quality, the recipient’s age may still influence implantation and pregnancy continuation.

Importantly, this does not mean women over 40 should not attempt treatment. Many older recipients achieve successful pregnancies – especially when the uterus is healthy and properly prepared. Rather, the data show that success rates gradually decline, and greater persistence may sometimes be required.

The Importance of Careful Medical Assessment

Because the uterus plays such a critical role, a thorough pre-treatment evaluation is essential.

This typically includes:

  • Assessment of the uterine cavity (to rule out polyps, fibroids, adhesions, or structural abnormalities)
  • Measurement of endometrial thickness
  • Ultrasound evaluation of uterine health
  • Review of general medical conditions

Doctors may also use individualized hormone preparation protocols to optimise the endometrium and enhance implantation potential.

Ensuring that the uterine environment is healthy and receptive significantly improves the likelihood that a high-quality donor embryo will result in a successful pregnancy.

How These Findings Are Used in Practice

These data are used to guide counselling and personalise treatment – not to exclude patients based on age. Each case is assessed individually, and treatment plans are tailored to maximise safety and success.

Successful pregnancy after globozoospermia IVF and ICSI treatmen

Key Message

Donor eggs are the main driver of IVF success because the donor’s age determines embryo quality. However, recipient age still plays a role in implantation and pregnancy maintenance.

After the age of 40, success rates gradually decline, and implantation failures and pregnancy losses increase. With careful assessment, proper uterine preparation, and personalised treatment planning, many women of advanced reproductive age still achieve successful pregnancies.

If you are considering IVF with donor eggs, an individual consultation will help clarify your personal prognosis and the steps needed to give you the best possible chance of success.

Understanding Frozen Embryo Transfer (FET)

Frozen embryo transfer (FET) is an established IVF technique that allows embryos created during an earlier IVF cycle to be stored and transferred at a later time. By separating embryo creation from embryo transfer, FET offers flexibility in treatment planning and allows transfer to take place when the uterus is optimally prepared.

This article explains how frozen embryo transfer works, the role of embryo storage, and how FET fits into an overall IVF cycle, including the use of blastocyst-stage embryos.

What Is Frozen Embryo Transfer?

Frozen embryo transfer is a procedure in which an embryo that has been previously frozen is thawed and transferred into the uterus. The embryo is typically created during an IVF cycle and preserved using advanced freezing techniques.

Unlike fresh embryo transfer, FET does not take place immediately after egg retrieval. Instead, the transfer is scheduled in a later menstrual cycle, allowing the body time to recover and the uterine lining to be prepared under controlled conditions.

How FET Fits Into an IVF Cycle

An IVF cycle generally includes several stages:

  1. Ovarian stimulation and egg retrieval
  2. Fertilisation and embryo development
  3. Embryo transfer or embryo freezing

When embryos are frozen rather than transferred immediately, the IVF cycle is divided into two phases:

  • Embryo creation and storage
  • FET cycle

This separation allows the transfer to occur at a time that may be more suitable for implantation.

The Role of Embryo Storage

Embryo storage plays a key role in frozen embryo transfer. After fertilisation, embryos are monitored in the laboratory and may be frozen at a specific stage of development, most commonly the blastocyst stage.

Modern cryopreservation techniques allow embryos to be stored for extended periods without compromising their potential for use in future treatment cycles. Stored embryos may be used for:

  • Future pregnancy attempts
  • Family planning over time
  • Delayed transfer for medical or personal reasons

The decision to freeze embryos is always made as part of a personalised treatment plan.

What Is a Blastocyst and Why Is It Important?

A blastocyst is an embryo that has developed for several days after fertilisation and reached a more advanced stage of growth. Blastocyst-stage embryos have undergone early developmental milestones and are closer to the stage at which implantation naturally occurs.

In FET:

  • Embryos are often frozen at the blastocyst stage
  • Transfer timing can be aligned with uterine receptivity
  • Laboratory monitoring helps support embryo selection

Not all embryos reach the blastocyst stage, and this is considered a normal part of IVF treatment.

How a FET Cycle Works

A FET cycle focuses on preparing the uterus rather than stimulating the ovaries.

Typical steps may include:

  • Monitoring the menstrual cycle
  • Preparing the uterine lining, with or without medication
  • Thawing the selected embryo
  • Transferring the embryo into the uterus using a minimally invasive procedure

The embryo transfer itself is usually quick and does not require anaesthesia.

Potential Benefits of Frozen Embryo Transfer

Frozen embryo transfer may offer several practical and clinical advantages, depending on individual circumstances, including:

  • Flexibility in treatment timing
  • Reduced physical demands compared to a full IVF stimulation cycle
  • Ability to plan transfer when the body is ready

Your fertility specialist will advise whether frozen embryo transfer is appropriate as part of your treatment plan.

Is Frozen Embryo Transfer Right for You?

FET may be considered if:

  • You have embryos stored from a previous IVF cycle
  • A fresh transfer was not recommended or postponed
  • You are planning future pregnancy attempts using stored embryos

Every patient’s situation is unique, and suitability for FET depends on medical history, treatment goals, and individual fertility factors.

Final Thoughts

Frozen embryo transfer is an integral part of modern IVF treatment, offering flexibility and personalised timing within the fertility journey. Understanding how embryo storage, blastocyst development, and IVF cycles work together can help patients feel more informed and confident when considering FET.

A consultation with a fertility specialist is the best way to determine whether frozen embryo transfer aligns with your individual treatment plan.