What is ovarian reserve? Why is it important for pregnancy?

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The ovarian reserve constitutes the pool of oocytes present in a woman’s ovaries, and it is an important indicator for assessing reproductive capacity, especially in the context of potential assisted fertilization treatments offered by Fertilab clinic.



The stock of follicles capable of generating oocytes is influenced by several factors:

  • Genetics
  • Age of the woman
  • Traumatic events affecting the ovaries (such as surgical interventions or therapies)

In general, the production of gametes, namely spermatozoa and oocytes, differs significantly between the two sexes, both in terms of the process and the quantity.

In men, spermatozoa are produced from puberty throughout life. In women, however, this possibility is absent, as they are already born with a well-defined number of cells. Once these cells are depleted, their reproductive capacity ends, marking the onset of menopause.

By the time of the first menstrual cycle, their number has already more than halved, and on average, only 400,000 remain, as the rest has been absorbed by the ovaries. From these, only around 300-500 oocytes will develop into mature eggs, and these are the ones a woman has available for conception.



Ovarian Reserve and Aging

This is the main reason why the quality and quantity of oocytes decline with age, making conception more difficult.

Our center offers ovarian reserve measurement, especially in the context of assisted fertilization treatments, in order to assess and personalize the medications used to stimulate follicle growth in assisted reproductive techniques.

There are numerous parameters for evaluating ovarian reserve, but measuring FSH levels is one of the most commonly used methods.

Typically, FSH testing is accompanied by estradiol testing, a particularly valuable subtype of estrogen. Both hormones are measured through blood tests.



Examinations for Assessing Ovarian Reserve

To conduct a more thorough and accurate investigation, it is possible to include the following tests:

Anti-Müllerian hormone (AMH): This hormone is produced by cells in individual follicles and provides an indirect idea of the number of follicles present. Excessively high levels may indicate polycystic ovary syndrome, which could be an underlying cause of infertility. AMH is versatile, as it can be measured at any point in the menstrual cycle, and its levels tend to decrease with age due to the progressive and physiological reduction in the number of follicles. Overall, it is one of the most reliable tests, especially when combined with follicular monitoring.

Count of antral follicles: This is a simple examination that requires an ultrasound. Since antral follicles are visible on ultrasound, they can be accurately counted, providing a real estimate of potentially fertilizable immature eggs in the future. This test, performed by our experts at Fertilab, is particularly useful for predicting the outcomes of in vitro fertilization.

In the absence of other fertility issues within a couple, ovarian reserve is the best parameter for understanding the chances of pregnancy, whether through natural conception or assisted reproductive techniques. However, it should be noted that ovarian reserve is simply a quantitative measure and not a qualitative one, so it cannot be regarded as a 100% reliable tool for conception.



Ovarian Reserve Screening

Many gynecologists propose conducting a general screening for women to raise awareness about their ovarian reserve and help them make informed decisions regarding the best time to have a child. It is possible for young women, for example, to have a reduced ovarian reserve without being aware of it, which is a classic case of early menopause. This examination allows for a relatively accurate calculation of when menopause will occur regardless of the age at which it is performed. It is useful for assessing oocyte cryopreservation in specific contexts and equally important when undergoing in vitro fertilization (IVF) treatment. It can provide valuable information about potential outcomes of ovarian stimulation (such as fewer follicles and fewer oocytes retrieved) and help balance the appropriate hormone therapy, including the prevention of hyperstimulation.

In addition to age, there are many factors that can prematurely reduce ovarian reserve levels:

  • Oncological treatments involving radiation therapy or chemotherapy
  • Genetic disorders such as chromosomal abnormalities or carriers of the FMR1 mutation or fragile X syndrome
  • Family history of early menopause
  • Ovarian surgery
  • Gynecological conditions such as endometriosis
  • Autoimmune disorders
  • Smoking
  • Exposure to pollutants or endocrine disruptors

But in the case that a woman, even a young woman, has a low ovarian reserve, what actions can be taken, and how should this result be interpreted?

Generally, we refer to a woman having a low reserve when there is an altered antral count and/or a decrease in AMH levels. If the patient is over 40 years old, the possibility of achieving a pregnancy decreases, even with assisted reproductive techniques such as in vitro fertilization.

It is important to emphasize that having a low ovarian reserve is completely asymptomatic, so a woman will not be aware of it unless she undergoes one or more of the tests mentioned above.



Preserving Ovarian Reserve

Therefore, there are some factors to consider:

  • Do not delay the desire for pregnancy: Even when facing a normal or high ovarian reserve, a woman’s chances of becoming a mother decrease significantly after the age of 35.
  • If pregnancy is desired to be delayed for various reasons (economic, social, personal), or if there are risk factors, particularly of a pathological nature, there is the option of undergoing ovarian stimulation and oocyte vitrification treatment. This treatment does not guarantee a future pregnancy in any case but increases the chances, especially if maternity is desired beyond the age of 35-37.
  • If there is suspicion of a low ovarian reserve, it does not necessarily mean a negative prognosis. In these cases, the probability of successfully achieving a pregnancy is lower but not zero. Therefore, it is essential to rely on a qualified consulting team that can guide the couple towards the most suitable path for them.


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