Ovarian stimulation
What is ovarian stimulation?
It consists of inducing multiple ovulation by means of hormonal medication.
During the spontaneous menstrual cycle, many follicles begin to develop in each ovary, but when one of them reaches a slightly larger size, the growth of the others is inhibited; the treatment aims to make several follicles develop to full maturity in the same cycle.
What is a follicle?
It is the place in the ovary where the oocyte, the female reproductive cell, develops. During the first phase of a woman’s menstrual cycle, the follicle develops, starts out microscopic in size and grows and fills with fluid containing nutrients for the oocyte up to about 18 – 22 mm. At this point a hole opens in the wall of the follicle and the oocyte comes out; this is ovulation.
How long does the ovarian stimulation phase last?
Usually about 12-14 days, during which time the patient should receive an injection every day, which can be subcutaneous or intramuscular depending on the medication regimen chosen for her.
What is the most appropriate medication regimen for each patient?
The schedule is established based mainly on the patient’s age, ovarian morphology, hormone analysis, body mass, response to stimulation in previous cycles, if any, and our experience.
We believe it is very important to indicate the most appropriate medication and doses for each woman, individualising each case and avoiding standard treatment guidelines as each patient has unique characteristics.
Are the medications expensive?
Yes. They are female hormones obtained by recombinant engineering and similar to those secreted by the female body throughout the cycle.
What are the risks of the medications?
There have been many studies on possible illnesses and cancer risks from taking these drugs, but it has not been proven that they are a cause of subsequent pathology.
If there is an excessive response it can lead to ovarian hyperstimulation syndrome.
Can IVF be performed without ovarian stimulation?
Yes, but the chances of evolutionary pregnancy are less than 5%. For this reason we do not do it in our centre. When less than three follicles develop, we prefer to discard the cycle as the chances of success are very low.
What do the stimulation controls consist of?
A blood test to determine the levels of oestradiol, which is the hormone produced by the growing follicles and a vaginal ultrasound to see how many follicles are developing in the ovaries and what size they are.
Based on these tests, the dose of medication is adjusted and the next check-up is indicated 1 or 2 days later. When the follicles have reached a size equal to or greater than 18 mm in diameter and the oestradiol levels are adequate, the injection of HCG is indicated. This hormone induces the final maturational changes and ovulation.
