Hormonal stimulation of ovulation: many women who undergo infertility treatment by in vitro fertilization (IVF) are often interested in questions:
- Do hormonal drugs used during IVF reduce the ovarian reserve?
- Won’t all the follicles be taken away during ovarian puncture?
- Will hormonal stimulation bring the onset of menopause closer?
As part of this short article, we will try to answer the questions posed. And let’s start with the theoretical part.
Hormonal stimulation of ovulation
Ovarian (ovarian) reserve is an internal reserve of the ovaries, which determines their ability to develop a healthy follicle with a full-fledged egg. The ovarian reserve not only reflects the total number of follicles contained in the ovaries, but also their functional state.
The follicular reserve is laid in utero, is not replenished during a woman’s life, does not increase, is individual, and normally by the time of the formation of menstrual function, a girl has an average of 270,000- 470,000 follicles.
During one menstrual cycle, as a rule, one follicle grows and reaches the ovulation stage. On average, 400-500 follicles reach ovulation in a woman’s entire life, and the rest undergo atresia (reverse development). Thus, with each menstrual cycle, the total number of follicles decreases, and with their complete disappearance, menopause occurs. The mechanisms of atresia and apoptosis ensure the survival of the strongest follicles, in which genetically healthy oocytes are most likely to mature.
In natural conditions, by the beginning of the next menstrual cycle, a cohort of antral follicles is formed in a woman, of which one pre-ovulatory is isolated by the time of ovulation, while the rest undergo reverse development.
Hormonal drugs used during the IVF program, the so-called “ovulation inducers”, have an effect on almost all follicles that have reached the antral stage, without affecting the entire ovarian reserve. Thus, in a stimulated cycle, it is possible to obtain high-quality eggs even from those follicles that would be “lost” to a woman under natural conditions. From this it can be concluded that stimulation does not lead to premature depletion of the follicular apparatus, does not reduce fertility and, thereby, does not bring the age of menopause closer.
All of the above confirms that the most important physiological factors determining the ovarian reserve are the genetic predisposition and age of the patient.
Studies conducted in recent years have shown that the rate of follicle disappearance doubles when the primordial pool is reduced to 25,000 follicles, which normally corresponds to the age of 37.5 years. This age is defined as critical, after which the ovarian reserve itself decreases sharply. However, there are significant individual characteristics in the time of menarche (10-16 years), the time of menopause (45-55 years), the onset of which is determined only by the individual biological age of a woman.
The correct selection of the stimulation scheme will allow you to get the optimal number of the highest quality eggs without causing any harm to health.