Ovarian stimulation is done with the so-called pituitary gonadotropins. The drugs that these hormones contain aim towards the controlled ovarian stimulation for the production of multiple follicles and hence, the production of ova. The administration of these drugs and their effects are controlled by the monitoring of the following two parameters: a) the increase in the size of the follicle with frequent ultrasounds and, b) the monitoring of a hormone in the blood called estradiol.
Monitoring and maturation of follicles
When the follicles have matured enough and estrogen levels have reached a satisfactory level then the administration of drugs is interrupted and another substance is administered called beta-chorionic gonodotropin at a specific point in time. This is a procedure aiming towards egg maturation. After 36-38 hours the woman comes to the IVF center for the collection of eggs.
Egg collection – egg retrieval
The collection of eggs is an easy procedure that takes place under mild sedation. It takes about 10-20 minutes depending on the number of eggs. Through an ultrasound and by using a fine needle a paracentesis of the follicles is performed and follicular fluid is drawn together with the egg. The egg is detected, isolated from the remaining cells of the follicular fluid and is maintained under appropriate conditions up until the point of fertilization.
Within an hour the female partner may leave the clinic, provided of course that she has recovered from the slight dizziness due to the anesthesia. The most painful part of IVF has now been completed.
After having completed the process of egg collection the male partner delivers the sperm in the laboratory to be processed and prepared for the imminent fertilization of the eggs. The collection of the sample can be performed in the lab within an hour. Alternatively, and only for specific reasons, the husband can provide a sample in the days preceding the egg collection, which can be cryopreserved (if possible). The thawing and the use of the sample take place on the day of oocyte retrieval.
Coupling of egg and sperm – fertilization
The fertilization takes place in the laboratory by highly trained personnel. On the day of oocyte retrieval the fertilization of the eggs is performed with the sperm of the male partner or the sperm of an alternative donor, provided that the couple has been informed about this and has decided to proceed with the procedure. After about 18 hours the couple will be able to know, how many eggs have been fertilized.