Ovarian Reserve: What It Is and How It Can Affect Female Fertility

A woman’s ovarian reserve is the number of eggs she has. This number varies depending on her age. Therefore, the ovarian reserve plays a decisive role in female fertility.

A low ovarian reserve can reduce a woman’s chances of becoming pregnant. However, having a high number of eggs is not the only factor in determining pregnancy. The quality of the eggs also plays an important role.

It is therefore important to determine both the quantity and quality of a woman’s eggs when recommending the most appropriate fertility treatment for her case.

What is ovarian reserve?

When we talk about ovarian reserve, we refer to the number of eggs a woman has at a specific moment, as the ovarian reserve varies over time. To understand the variation in women’s ovarian reserve, we must consider their fertile period. From the age of 16 to 30, the quantity and quality of a woman’s oocytes are good.

Between the ages of 35 and 37, there is a significant decline in ovarian reserve, affecting both the quantity and quality of the eggs. From the age of 40, the female ovarian reserve is compromised. Between the ages of 45 and 55, it can become depleted, marking the beginning of a new reproductive stage, menopause.

Although this is generally what happens with ovarian reserve among women, it is not always the case. We must consider that, due to various factors and reasons, the decline in the quantity and quality of ovarian reserve can occur earlier in some cases, leading to premature menopause.

What we must be clear about is that ovarian reserve is crucial for achieving pregnancy, whether naturally or through assisted reproduction techniques.

How to determine it?

As mentioned earlier, a woman’s ovarian reserve varies depending on the moment she is in. We must consider that women are born with around one million oocytes, which decrease to 400,000-500,000 by the time they reach puberty.

And, for each monthly menstrual cycle, only between 400-500 oocytes will reach ovulation, and the rest will be lost. Calculating a woman’s ovarian reserve is not something we can do at home; instead, a specialist must be consulted to accurately determine the quantity and quality of the oocytes available at that moment.

The tests that will be performed to determine our ovarian reserve are:

• A gynaecological ultrasound to perform a follicle count.• A blood test to determine the levels of anti-Müllerian hormone and to know the number of available follicles.

The fertility specialist can evaluate your ovarian reserve through these two tests. Thus, they can tell you if it is a good time to preserve your fertility if you wish to delay motherhood.

If, on the other hand, you are looking to become a mother now, they will recommend the best method to achieve it when they give you the results. This will help you make informed decisions about your motherhood based on your current situation.

What are the causes of decreased ovarian reserve?

The main factor in the decrease of ovarian reserve is the woman’s age. The older she is, the fewer eggs she has, and their quality also decreases.

However, there are other external factors that also contribute to the decrease, both in quantity and quality, of women’s eggs and affect their ovarian reserve:

• Having undergone radiotherapy or chemotherapy treatments.• Stress.• Obesity.• Conditions such as endometriosis or pelvic infections.

Therefore, treatments such as egg freezing can help us in the future if we want to delay motherhood and will help preserve the best quality eggs.

How does ovarian reserve affect an In Vitro Fertilisation treatment?

When undergoing an IVF assisted reproduction treatment, it is important to know in advance not only the woman’s ovarian reserve but also the quality of the eggs, i.e., their oocyte quality. Over time, a woman’s eggs decrease in quality and quantity until menopause.

If the ovarian reserve is not adequate, the treatment cannot be successfully carried out. In this case, other options such as using donor eggs will have to be considered.

Low ovarian reserve and pregnancy

Having a low ovarian reserve does not mean that pregnancy cannot be achieved. There are more factors to consider when it comes to pregnancy, and not all are closely linked to the woman. The quality of the man’s sperm or genetic diseases that can be transmitted to the embryo can also play a role.

Having unprotected sex for a year without achieving pregnancy can be a sign of infertility in the couple. In this case, it is advisable to consult a specialist so that both individuals can undergo the necessary tests to determine the cause and find a solution.

However, a low ovarian reserve will delay the desired pregnancy. Therefore, detecting it in time can help increase your chances of pregnancy.

Can ovarian reserve be increased?

A woman’s ovarian reserve cannot be increased. In fact, it decreases over time until there are no oocytes left. This stage, when a woman loses all her eggs, is known as menopause.

Although ovarian reserve is limited and different for each woman, there are various assisted reproduction techniques that can help you become a mother in the future with your own eggs.

Egg freezing is one of the techniques that helps women preserve their fertility and choose the right time to start their journey to motherhood.

At our IVF-Life clinics, we provide you with the best professionals in the field of reproductive medicine. The specialists can advise you on the fertility treatment that best suits you and your circumstances, always based on a prior study of your fertility and that of your partner.