In vitro fertilization is a fairly complex procedure that takes place in several stages:
– Ovarian stimulation: A daily hormonal treatment is administered to the woman to stimulate hormonal secretion from the follicles. The response to the treatment is monitored by ultrasound. Ovarian stimulation controls follicular growth to ensure that a sufficient number of mature oocytes are obtained, ready to be fertilized.
– Oocyte retrieval : This step is done under anesthesia (general or local), 34 to 36 hours before the oocyte retrieval. It is monitored by ultrasound. The doctor locates the mature oocytes in order to retrieve them using a needle and a small tube introduced into the vagina. The oocytes are then selected in the laboratory. The sperm is usually collected the same day. If it has been collected before, it is thawed a few hours before fertilization.
– Follicle puncture: The collected oocytes and sperm are brought together the same day. Fertilization takes place in culture media with a composition similar to the natural environment of the fallopian tubes. No intervention is done from then on, the fertilization process occurs spontaneously.
– Embryo transfer: Using a thin catheter, the doctor transfers and deposits the embryo in the woman’s uterus, where it will gradually develop. This step takes place approximately 2 to 5 days after the puncture.