In vitro fertilization takes place in a laboratory. In order to achieve a successful pregnancy, spermatozoids which have been isolated from the semen, and eggs are needed. The eggs are extracted through the vagina by drawing out the follicular liquid where the eggs are to be found.
It is necessary to stimulate the ovaries with a hormonal stimulation in order to produce more than one ovum in the same period. This stimulation is monitored via ultrasound scan and analysis. When the follicles are of an adequate size to allow the ovum to mature the ovarian puncture will then be carried out, a surgical process which takes place under sedation. It normally takes about 20 minutes, after which the patient is required to rest. If after 4 or 5 hours the patient does not experience any discomfort she will be allowed to go home and continue normal activity.
A biologist examines the follicular liquid in order to isolate the ova. Subsequently the semen sample is prepared and once the spermatozoids have been separated they are deposited with the eggs so that fertilization may take place.
The next day we observe whether the fertilization has taken place correctly. 24 hours must pass before the zygote divides and we obtain an embryo of two cells.
The transfer of embryos to the uterus of the patient is usually performed 48 to 72 hours after the ovarian puncture.
We select the number of embryos to be transferred (one, two or three) depending on the couple's history, age and the quality of the embryos.