The ovaries are stimulated with daily administration of injections in order to develop several eggs rather than a single egg as it occurs in a natural cycle. This way a large number of embryos can be created after the fertilization of the oocytes. This treatment usually takes from 10 to 20 days, depending on the treatment protocol used and on each woman’s response.
During the treatment, usually 3-4 ultrasounds take place as well as blood sampling for hormone measurement (estradiol, etc.), in order to monitor the development of the ova.
When the follicles are mature, we plan the egg retrieval about 36 hours after the administration of HCG, which promotes the final egg maturation exactly as it occurs in the natural cycle. Oocyte retrieval takes place in the operating room under light anesthesia (sedation) so that the patient does not feel any discomfort or pain during the process, which typically takes 10-15 minutes. The oocytes are aspirated transvaginally with a sonographically guided needle.
After the egg retrieval, semen is provided by the male partner so as to proceed with the fertilization of the ova. The process of fertilization is carried out either via classical IVF, during which a few thousand spermatozoa are placed around an egg or via ICSI, in which a single live sperm cell is selected and inserted into the egg by the embryologist.
The day after the fertilization, the embryos are “graded” depending on their morphological characteristics and their ability to divide. Some may not have evolved and get discarded because they are considered unsustainable.
The best embryos are selected for transfer into the uterus of the mother 2- 5 days after the retrieval. Embryo transfer is performed with a special catheter. The whole process takes place in the operating room, no kind of anesthesia is needed, it is painless and does not last long.
The remaining good quality embryos are cryopreserved by the vitrification technique and may be used in the future without the need of ovarian stimulation or drug therapy.