HUMAN REPRODUCTION
TREATMENTS
OVARIAN STIMULATIONOVARIAN STIMULATION
Ovarian stimulation is one of the most important tools in the fight against infertility and consists of stimulating the ovarian follicles (structures that contain the eggs) through the controlled use of hormones. This technique is an essential requirement for any assisted reproduction method, whether we are talking about ovulation induction, intrauterine insemination (IUI), or IVF/ICSI, with different levels of intensity in each case.
How does it work?
Each ovarian follicle contains one potential egg. In a natural menstrual cycle, regulated by hormones produced by the ovaries or the pituitary gland, many follicles are prepared to grow, rupture, and release their eggs. However, only one egg is released per cycle, while the other follicles are simply lost.
Ovarian stimulation, performed with hormones similar to the body’s natural ones but at higher doses, allows these follicles, instead of being “wasted,” to produce their eggs. These eggs can be used immediately for conception or even frozen for future use (cryopreservation). Either way, the chances of fertilization and pregnancy increase considerably.
In ovulation induction and IUI treatments, the goal is to stimulate only 1 to 3 follicles for ovulation. In IVF/ICSI, however, the goal is to stimulate most of the follicles available during that cycle. There are various medications available, and for each case, a specific medication and dosage are determined. Specialists also monitor the response to stimulation through transvaginal ultrasounds, allowing them to control and adjust hormone doses as needed.
One risk: Ovarian Hyperstimulation Syndrome (OHSS)
When ovarian stimulation results in an excessive ovarian response, inducing more than 20 follicles to ovulate, this is known as Ovarian Hyperstimulation Syndrome, or OHSS. A high concentration of estrogen resulting from this adverse follicular response causes a range of symptoms, the most common being enlarged ovaries and fluid accumulation in the abdominal cavity.
At this stage, monitoring by a specialist physician is necessary to adjust hormone dosages and provide specialized treatment.
It is also important to remember that pregnancy should not occur during a cycle in which OHSS develops. Therefore, all eggs produced must be frozen (freeze-all) to be fertilized and transferred in a subsequent cycle.
