By Neus Ferrando Gilabert BSc, MSc (embryologist).
Last Update: 04/15/2014

The quantity of eggs that a woman has in her ovaries can be measured through a blood analysis.

The number of primordial follicles, that will eventually give rise to fertile eggs, can be detected through a blood analysis by measuring the concentration of the Anti-Müllerian hormone at any given point in the menstrual cycle. This marker of the ovarian reserve was founded by a group of Argentinian researchers, back in 2009. Nowadays, there are many clinics that analyze the presence of this hormone when they suspect that there might be a dicrease of the ovarian reserve.

The ovarian reserve decreases with the age

During the fetus stage, in week 20, the baby girl has in her gonads the maximum number of primordial follicles that she will have during her lifetime. This number is around 5,000,000 primordial follicles. When the first period comes -known as “menarche”– this number has gone down until 500,000 follicles. In each cycle, around 1000 follicles will start maturing, but only one will release an egg. This only egg will go through to Fallopian tubes and the rest of the follicles will be useless.

The number of eggs available to become pregnant decreases as the woman gets older, because the ovaries get, biologically speaking, worse.

This is why when a woman begins to try to get pregnant, she does not know how good her ovaries (and her eggs) are.

Whether the ovaries of a healthy woman have the optimal quantity and quality of fertile eggs is hard to know, even in those cases where the woman has normal cycles or she has no background history of these kind of problems.

The number of follicles decreases as the woman gets older.

Detecting the AMH as a marker of the ovarian reserve

The Anti-Müllerian hormone is detected by means of a simple blood test. This hormone is an important factor in the growth of the ovary. It also regulates the development of the eggs avoiding thus, an excessive waste of follicles in each cycle. For this reasons, this hormone is regarded as a self-protection mechanism of the ovary; it helps the ovary to preserve itself by not letting too many follicles to be wasted in each cycle.

Some worlwide studies confirm that the presence of the AMH is a proportional marker of the number of follicles: the higher the levels of AMH, the higher the number of eggs in the ovary. This hormone portrays the response of the ovary when facing the ovarian stimulation, instead of reflecting a late estimation when the fertility treatments have failed.

What is more, this hormone is also used with patients that underwent treatment that affected their ovaries (for example, with chemotherapy treatments), causing an impact on their ovarian follicles, which leads to a dramatic drop-off of the number of fertile eggs. In those cases, the AMH can help planning a personalized reproductive treatment.

Authors and contributors

 Neus Ferrando Gilabert
BSc, MSc
Embryologist
Bachelor's Degree in Biology from the University of Valencia (UV). Postgraduate Course in Biotechnology of Human Assisted Reproduction from the Miguel Hernández University of Elche (UMH). Experience managing Embryology and Andrology Labs at Centro Médico Manzanera (Logroño, Spain). More information