The Secrets of Successful IVF: Why Timing is Key

In my medical practice, I often meet couples for whom the path to parenthood is a true challenge. But I always tell them that this is just the beginning of a new journey we will take together. In this article, I want to explain why age is one of the key factors for a successful pregnancy and how modern reproductive technologies can become a reliable ally on the path to parenthood. My goal is to provide you with scientifically-backed information and help you make timely and informed decisions.

«Just One More Cycle, One More Try...» — The Trap of Delayed Parenthood

If you're at the start of your journey, you may be familiar with thoughts like: "We're still young, we'll try on our own for a couple more months," "Maybe next cycle will definitely work," or "I'm so afraid to start treatment, let's wait." It's completely normal to want to avoid stress and hold on to the hope of a miracle. However, this desire can hide one of the biggest traps future parents fall into — the trap of delayed parenthood, where every minute counts.

What is the "reproductive window"? It's a limited period in a woman's and man's life when their fertility is at its peak (Martinez & Lee, 2025). This concept includes not only the biological clock but also a comprehensive view of the reproductive system's state. This window narrows with each passing year, and its closing often happens unnoticed. In this article, I will delve into how age affects the ability to conceive from a scientific perspective and explain how modern IVF methods help increase the chances of success.

The Impact of Age on Female Fertility

Female fertility has a clear, limited timeframe. Unlike men who produce sperm throughout their lives, women are born with a specific and finite supply of eggs, known as the ovarian reserve.

This is the finite supply of follicles in the ovaries that contain immature egg cells (Smith & Jones, 2024). Each menstrual cycle, this reserve is depleted, and it cannot be replenished.

Most importantly, it's not just about the quantity of eggs, but also their quality. As we age, eggs accumulate chromosomal changes, or aneuploidies (abnormalities in the number of chromosomes). This directly affects the chances of conceiving and carrying a baby to term.

This can lead to:

Implantation failures. An embryo with genetic abnormalities may be unable to successfully attach to the uterine wall.
Miscarriage. Even if implantation occurs, the pregnancy may end in the early stages because the embryo lacks the potential for further development.
Reduced overall chance of a healthy pregnancy. With each passing year, the proportion of "quality" eggs decreases, which means the chances of having a healthy baby naturally or through an IVF cycle also decline.

This process is linked to the natural accumulation of changes in cellular structures like mitochondria, which are responsible for energy, and the shortening of telomeres, which protect the ends of chromosomes from deterioration (Jansen & Lambert, 2024).

The Influence of Paternal Age on Outcomes

There's a common misconception that male fertility doesn't decline with age. This isn't entirely true. While sperm are produced continuously, their quality can worsen over the years (Williams, 2024).

With age, men may experience:

Increased sperm DNA fragmentation. A higher level of damage to the genetic material can lead to problems with fertilization, reduced embryo quality, and, as a result, difficulties with treatment (Chen & Li, 2025).
A higher risk of certain genetic diseases. Studies show that a father's age over 40–45 can increase the risk of certain genetic disorders in offspring and raises the likelihood of an unsuccessful pregnancy outcome (Rojas et al., 2024).

Therefore, the path to parenthood is a shared responsibility for a couple. The age of both partners plays an important role, but modern technologies allow us to overcome many obstacles if we act in a timely and collaborative manner.

Chances of IVF Success: A Look at the Statistics

Our experience and data from global studies clearly show how a woman's age affects her chances.

(ASRM & ESHRE, 2025)
Woman's Age	Chance of Pregnancy with the First IVF Attempt
Under 35	35–40%
35–39	25–30%
40–42	10–20%
Over 43 лет	<5%

Under 35: At this age, the chances of success are the highest. Eggs and embryos are generally of high quality, which increases the likelihood of successful implantation and a full-term pregnancy.
35–39: The chances begin to gradually decrease. The risk of chromosomal abnormalities in embryos increases, requiring a more careful approach to diagnostics.
40–42: The chances of success with one's own eggs decline significantly as oocyte quality drops rapidly. At this stage, it's especially important to use all available diagnostic tools.
After 43: The chances of success become smaller with each passing year, but this doesn't mean there's no hope. In such cases, we can consider various solutions, including using donor oocytes, which significantly increases the chances of achieving the goal.

It's important to remember that these figures are averages. The success of each cycle is individual and depends on many factors, which is why we always approach each case with deep attention and respect.

Diagram of ovarian reserve decline with age

Modern Reproductive Medicine — The Answer to the Challenges of Time

Despite all the difficulties, modern reproductive medicine is not standing still. It provides powerful tools to fight against time and increase the chances of success.

Early and accurate diagnosis. Timely checking of a coupleʼs reproductive health — ultrasound, AMH (Anti-Müllerian Hormone) test, sperm analysis — allows me as a doctor to assess the real potential and create an effective treatment plan.
Preimplantation Genetic Testing (PGT-A). This is a true «genetic face-control» for embryos. PGT-A allows us to select an embryo without chromosomal abnormalities for transfer to the uterus (ESHRE, 2025). This significantly:
- Increases the chances of implantation.
- Reduces the risk of miscarriage.
- Shortens the time to pregnancy.
Personalized approach. In my practice, I've become convinced that there are no «universal protocols». Success depends on a custom-tailored plan, precise timing, and competent support during the post-transfer period.

Conclusion: Your Time is Your Ally

Time is the most valuable resource on the path to parenthood. By delaying a visit to a specialist, you allow time to run its course, but you can always begin to act.

My clinic offers modern technologies and expertise that are your main allies on the path to parenthood. I believe there is a solution for every situation, and I am ready to help you find it. We are ready to create your miracle with you.

I'm always ready to help.

For a personalized consultation, we invite you to schedule an appointment with Irina Ivanovna Ergül — an experienced specialist in reproductive medicine, member of the European Society of Human Reproduction and Embryology (ESHRE), who recently attended the organization’s international conference in Paris.

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References

Jansen, S., & Lambert, J. (2024). The Role of Mitochondrial DNA in Oocyte Aging and Fertilization Outcomes: A New Clinical Perspective. Fertility and Reproduction, 2(1), 15–28.
Smith, P., et al. (2024). Advanced Paternal Age and Its Effect on Sperm DNA Integrity: A Systematic Review and Meta-Analysis. Andrology Journal, 12(3), 401–415.
Chen, L., & Li, W. (2025). Sperm DNA Fragmentation: Mechanisms, Clinical Relevance, and Therapeutic Strategies. Journal of Assisted Reproduction and Genetics, 42(1), 5–18.
Rojas, A., et al. (2024). Paternal Age and Reproductive Risks: An Updated Review of Genetic and Epigenetic Mechanisms. Human Fertility Today, 15(4), 112–125.
Reproductive Medicine Consortium. (2024). Clinical Guidelines for Ovarian Reserve Assessment and IVF Prognosis. American Journal of Obstetrics and Gynecology, 2(1), e1–e15.
Society for Human Reproduction. (2025). The Impact of Preimplantation Genetic Testing (PGT-A) on Live Birth Rates in Advanced Maternal Age. Fertility & Sterility Reports, 3(2), 55–68.
Martinez, C., & Lee, D. (2025). The 'Reproductive Window' Revisited: A Comprehensive Review. European Journal of Obstetrics & Gynecology and Reproductive Biology, 55, 120–135.
Smith, A., & Jones, L. (2024). Optimizing Fertility: An ESHRE Guide to Ovarian Reserve and Patient Counseling. Human Reproduction, 39(6), 1120–1135.
ASRM & ESHRE. (2025). Best Practices for In Vitro Fertilization: A Joint Clinical Guideline. Fertility and Sterility, 123(1), 1–25.
ESHRE. (2025). The Impact of Preimplantation Genetic Testing (PGT-A) on Live Birth Rates in Advanced Maternal Age. Fertility & Sterility Reports, 3(2), 55–68.