The Era Where Youth Guarantees Fertility Is Over
“I’m young, so why is my egg quality poor?”
This is one of the most frequent questions asked by women in their 20s and 30s undergoing fertility treatment. Even among young women, there are many cases where they repeatedly hear that their egg quality is poor during IVF (In Vitro Fertilization).
Most people believe that the eggs of a twenty-year-old and a woman in her early-to-mid thirties are healthy. They assume egg quality only starts to decline slowly after age 37, and that cases of significantly poor egg quality only appear after age 40. However, in clinical practice, there are cases where a thirty-year-old woman’s egg status is evaluated as being at a forty-five-year-old level, while there are also instances where women over forty produce surprisingly high-quality embryos.
For a long time, fertility treatment has been explained primarily through the lens of age. However, recent research is focusing on more complex biological factors that determine the quality of an egg.
What are the keywords that dictate egg quality? The most prominent is the mitochondrion.
Mitochondria are called the powerhouses of the cell. Because the egg is the largest cell in the human body, it requires an enormous amount of energy. The process of fertilization, cell division, and embryo growth essentially depends on the performance of the mitochondria. This is why researchers now say, “The age of the mitochondria is more important than the age of the egg.” It is also why mitochondrial dysfunction is identified as one of the causes of recurring poor egg quality in young women.
There are several other factors that degrade egg quality:
First, endometriosis cannot be overlooked. Endometriomas that occur in the ovaries are not just simple cysts. They create a chronic inflammatory environment around the ovaries and increase oxidative stress, which can deteriorate the very environment where eggs grow. In fact, many patients with endometriosis experience poor embryo development even when their AMH levels are normal.
Second, the same applies to Polycystic Ovary Syndrome (PCOS). Getting a large number of eggs does not mean a good result. Some patients undergo the retrieval of dozens of eggs, only to find they have almost no viable embryos left. This is because the quantity of eggs and the quality of eggs are completely different issues.
Third, blood sugar and insulin resistance are emerging as important variables. Even if a person is not obese and has never been diagnosed with diabetes, steady research results are being published showing that the existence of insulin resistance can change the environment inside the follicle. In the past, focus was placed only on the ovaries; now, we must look at the body’s overall metabolic state.
Fourth, it is no longer possible to ignore environmental hormones. In a society where plastic containers and disposable products are commonplace, global research is underway to analyze the effects of bisphenol A, phthalates, and microplastics on ovarian function. While not all causal relationships have been identified yet, it is becoming increasingly clear that germ cells are tissues that are extremely sensitive to environmental changes.
Finally, the most frequently omitted factor: the male factor. When IVF results are poor, many couples blame the egg first. However, studies are reporting that a significant portion of repeated embryo development failure is related to sperm DNA damage. These are cases where fertilization occurred normally, but the embryo stopped growing during development. Nevertheless, the structure remains where the responsibility for infertility is still placed more heavily on the woman.
There is an issue here that must be addressed: the tendency to explain poor egg quality in young women solely as a matter of individual lifestyle choices.
Of course, smoking, obesity, and sleep deprivation affect reproductive health. However, attributing every cause to lifestyle is less of a scientific explanation and more of an act of shifting responsibility. There are many women who experience recurring poor egg quality despite exercising regularly, managing their weight, and maintaining healthy eating habits.
An egg is not a cell created by effort alone. It is simultaneously influenced by numerous variables: genetic characteristics, cellular energy metabolism, inflammatory status, environmental exposure, hormonal balance, and the male factor.
Nevertheless, society still asks young women, “You’re still young, so why is it not working?” We must now acknowledge that this very question might be wrong.
Youth is an important condition for fertility, but it is not a sufficient one. Being twenty-nine does not guarantee excellent eggs, and the number forty-five does not necessarily mean the possibility of pregnancy is slim. Precision research and social interest are desperately needed to understand why the reproductive health of young women is wavering faster than expected, and why the eggs of some women are aging before their actual chronological age.
In an era where more women are working, policies and support to simply increase the birth rate are important, but it is even more urgent to create a society that fosters an environment where pregnancy occurs easily, and where pregnancy is encouraged and accommodated.