The sand of female fertility starts slipping through an hourglass the moment they hit puberty!

Females are born with a limited reservoir of 1 to 2 million eggs at birth.1 On top of that, the quality of these eggs keeps declining as your age progresses. Therefore, it is only natural that you should want to keep track of your fertility status as you navigate different phases of your life.

Let us dive deeper into how the quality and quantity of the eggs in your ovaries can affect your fertility. These should explain why you should monitor your fertility regularly for a seamless pregnancy experience.

Fertility Status In The Aging Female

As a woman, you experience your prime reproductive state during your 20s. As you approach the 30s, fertility gradually decreases, especially around age 35. A fertile and healthy woman between the age of 20 and 30 has a 25% chance of becoming pregnant per cycle when trying to conceive. However, these numbers take a steep dive and drop between 5% to 10% per cycle by the time a woman reaches the age of 40.2

In fact, women lose their fertility well before hitting menopause. Although menopause typically occurs between 45 and 55 years of age, most women start having trouble getting pregnant in their mid-30s.1 Female fertility status declines progressively with age because both the amount and quality of eggs steadily decrease.3 These statistics apply to both naturally occurring and artificial reproduction techniques, including in-vitro fertilization (IVF).4

The Number Of Eggs

The phrase "loss of ovarian reserve" refers to the ovaries' declining number of egg-containing follicles. Women start to lose their ovarian reserve much before becoming infertile or ceasing to have regular cycles. Women are born with all the follicles they will ever have. At birth, you are estimated to have around 2 million eggs, and the number naturally goes down to 400,000 eggs by puberty. This pool of premature follicles is steadily depleted after women start having their periods at puberty and only 400 to 500 reach maturity during their life.5

Gradually, the follicles become less responsive to FSH stimulation as ovarian reserve decreases, necessitating greater stimulation to cause an egg to develop and ovulate. Initially, the periods may start occurring closer to the previous one due to a lack of estrogen production in the ovaries, causing shorter, 21 to 25 days menstrual cycles.6 Irregular cycles eventually develop as the follicles lose the ability to respond adequately enough to the hormones to reliably ovulate.

Anti-Mullerian Hormone (AMH) is a good marker of ovarian reserve as it reflects the number of eggs in the ovaries. In most cases, the AMH levels are directly proportional to the ovarian reserve.7 However, sometimes women with PCOS are also found to have higher AMH in their blood.8 So, you should keep a track of your AMH through tests like the OvaScore to check your ovarian reserve or if you are experiencing any symptoms of PCOS.

The natural loss of eggs and the decline in the average quality of the eggs that are still present are the two main causes of diminished ovarian reserve. It is a condition wherein you have fewer eggs in your ovaries compared to women your age.9,10

However, smoking, a family history of early menopause, and prior ovarian surgery may all contribute to young women having a lower ovarian reserve.11

The Quality Of Eggs

Women become susceptible to miscarriages as they age because the quality of the eggs starts to decline with the number of remaining eggs. These changes in quality become more apparent as you enter your mid-to-late 30s.12 The older eggs have also been exposed to environmental toxins for a longer amount of time which causes some issues during the pregnancy. 13

The prevalence of genetic irregularities known as aneuploidy represents a significant decrease in egg quality (too many or too few chromosomes in the egg). A typical egg should have 23 chromosomes upon fertilization, and when that egg is fertilized by a sperm that has 23 chromosomes as well, the developing embryo should have the appropriate number of 46 chromosomes. As a woman ages, her eggs become ever more likely to have an abnormally high or low number of chromosomes.14 This indicates that if fertilization takes place, the embryo will likewise have an imbalance of chromosomes.

Such imbalances cause disorders like Down syndrome, which is brought on by an extra copy of chromosome 21. Most embryos that have too many or too few chromosomes fail to develop into pregnancy or miscarry causing a decline in the fertility status. This outlines why aged women have a decreased likelihood of getting pregnant and a greater chance of miscarrying.15 

Wrapping Up

Science is making excellent progress in extending the time frame of female fertility. We have artificial reproductive techniques like IVF and other options like freezing the eggs to preserve them for pregnancy whenever you feel ready for it. However, every woman deserves to understand their reproductive health and what it has in store for them. 

Regularly tracking your body’s changes through the OvaScore Test provides a detailed insight into your reproductive health. The results can help you make an informed plan whether you are actively trying to conceive or preparing for parenthood in the future.