From what I've read the issue is related to the number of healthy eggs the woman has left. Healthy eggs are more likely to be fertilized, but the healthier ones are the ones that get used up earlier so in later age the woman has a higher rate of unhealthy eggs so its more difficult to get pregnant.
So I guess there must be a relationship with the general health and attractiveness of the woman and the likelihood of her having healthier eggs in later age, if that helps.
Following information is from Extend Fertility, a feminist IVF and egg freezing service. Even their info is based on reality, yet women still remain delusional. Just smdh. The takeaways are my thoughts of the information.
As you age, a higher and higher percentage of the eggs inside your ovaries contain genetic abnormalities.
The eggs inside your ovaries are “primordial,” or immature eggs. As you ovulate, they go through another phase of cell division, known as meiosis. Older eggs are more likely to accumulate errors in their DNA during that division process, leading to genetically abnormal eggs.
Once a cell’s DNA is degraded, it can’t be fixed medically or “healed.” In other words, once an egg becomes abnormal, it can’t become normal again—egg quality cannot be improved. Egg quality is fairly black-and-white—either an egg is genetically “normal” (euploid) or it’s not (aneuploid), and as women age, a higher and higher percentage of their eggs become abnormal.
Since DNA is like an instruction manual for our cells, any damage to your DNA can prevent that cell from doing what it’s supposed to do—which, in the case of the egg, is make a healthy baby.
Takeaway: hitting the wall is a literal biological fact. Women who refuse to acknowledge the effects of aging are denying the fact that the DNA in their eggs are literally rotting away one at a time.
Egg quality declines over time
There’s no test for egg quality. The only way to know if an egg is chromosomally normal is to attempt to fertilize it, and, if fertilization is successful, to perform a genetic test on the embryo. But because DNA damage is inevitable in older eggs, your age can give doctors a fairly accurate picture of what percentage of your eggs will be genetically normal.
When we talk about a woman’s egg quality, we’re talking about the expected percentage of her total number of eggs that are normal. For better or worse,
this is purely a function of age. In stark contrast to the “wide range of normal” we see when it comes to egg count, the impact of age on egg quality is consistent and universal. In other words: women in their 20s will have mostly normal eggs, though they already have some abnormal ones. And women in their 40s will have mostly abnormal eggs—no matter how healthy a lifestyle they maintain.
Takeaway: mother nature doesn't care about your career, education, social status, or any other cultural construction.
Fertility and egg quality are directly connected.
Women’s ovaries are naturally programmed to allow just one egg to grow, mature, and be released (“ovulated”) each cycles (usually each month). That one egg represents the one chance for pregnancy in that particular menstrual cycle.
That egg ovulated may be either normal or abnormal. If it’s normal, great—you have a healthy pregnancy. But if it’s not? Abnormal egg cells typically don’t fertilize or implant in the uterus, but in the rare case they do, they can result in miscarriage or genetic disorders like Down syndrome.
The difference in egg quality between a 25-year-old and a 40-year-old is a
matter of the statistical likelihood of the one egg she’s ovulated being normal. Because women in their late 30s and 40s have a higher percentage of abnormal eggs, it’s much more likely that their one egg each month will be abnormal. That’s why natural fertility declines with age, and why we see infertility, miscarriage, and genetic disorders more often with women over 35.
Takeaway: eggs are limited in quantity. Fertilization is a complex and high cost (in terms of physical impact and risk for mother) event.
