Ovarian stimulation before egg retrieval
What is the difference between natural cycle and IVF stimulation?
Normally, an average of about 20 follicles (in which eggs grow) are prepared in a woman’s ovaries every month, but only one of the eggs matures and ovulates. In IVF procedures, it is desirable that this natural process of dominant follicle selection is suppressed and that as many mature eggs as possible are obtained in a single cycle.
After administration of hormones during stimulation, a larger number of follicles develop in the ovaries.Growing follicles produce estrogens, which, among other things, cause an increase in the level of luteinizing hormone (LH), which in the natural cycle allows the mature egg to be released from the ovary. During stimulation, a drug is administered that delays natural ovulation and prevents premature rise in LH.
Why are check-ups during stimulation with blood sampling and ultrasound performed at the Helios Sanatorium while not performed at other centers?
We consider the monitoring of stimulation by determining the values of hormones from the blood serum and ultrasound examination to be an absolutely fundamental and necessary step. Such checks are usually performed 3-4 times during stimulation, usually min. 5th, 8th and 11th day. On the one hand, it is a matter of obtaining a sufficient number of mature eggs, on the other hand, it is an effort to prevent an excessive reaction (hyperreaction), manifested by pain, significant ovarian enlargement and the formation of free fluid in the abdominal cavity (OHSS – ovarian hyperstimulation syndrome). More women under the age of 30 and women with the so-called PCO syndrome are at risk of this hyperreaction.
The tests performed (even repeated) have no side effects on oocytes or embryos in the early stages of pregnancy.
Are these checks really necessary? What if the patients are not from Brno?
Although it is less comfortable for the patient than stimulation without checks and needs to be adjusted in time, we know how useful these checks are. This is also confirmed by our more than 25 years of experience. Every woman reacts differently to stimulation. And in order for the result to be as good as possible – as many quality and mature eggs as possible – it is necessary to monitor the individual response and effectively manage the stimulation accordingly.
If the patient is outside Brno and has a district gynecologist who is willing to perform an ultrasound examination and blood sampling, it is possible to undergo the first examinations externally. The patient then only sends the result of the check to the co-ordinators. After evaluating the results by a doctor, the patient will then receive instructions on how to proceed.
How long does the stimulation last?
In our experience, stimulation should last for at least 12 days. Egg collection is then planned for day 14. If the follicles grow more slowly or unevenly, the stimulation can be extended. Ovulation (egg maturation) is induced by an injection of chorionic gonadotropin (hCG), which must be given approximately 32-36 hours before the scheduled egg collection.
What is used for the stimulation?
We only use stimulant preparations that combine FSH and LH. In exceptional cases, when a woman has more of her own LH (PCO), it is only possible to use a preparation with FSH, but at the same time we still monitor the levels of FSH, LH and E2 during stimulation and add LH if necessary. The physician decides on the beginning, duration and method of stimulation based on the hormonal profile, individual response, age and weight of the patient.
Administration of hormonal preparations does not prematurely deplete the supply of eggs in a woman’s ovaries, it only prevents natural degeneration and selection of the dominant follicle. According to current knowledge, it has no other negative effects on the human body.