In vitro fertilization in Tunisia
In vitro fertilization is a technique of collecting gametes of the couple to perform extracorporeal fertilization and transfer the embryos into the uterus. It is indicated mainly in tubal infertility (tubal obstruction) and in case of moderate alterations of semen.
It includes several steps it is important to understand to better accept the constraints:
- Ovarian stimulation.
- The oocyte collection.
- IVF properly so called.
- The transfer of embryos into the uterus.
The more oocytes we have in fertilization, the greater the chance of obtaining embryos. The ovulation stimulation promotes the recruitment and development to maturation of several follicles in the women’s ovaries. The treatment is carried in two stages:
– A blocking stage during which the woman is injected with a drug that blocks the production of gonadotropins by the pituitary gland. The hormone levels in blood assays to verify that the blockage was well received.
– A stage of stimulation: Once the blocking is achieved, a hormone is administered: FSH which stimulates follicle development. Appropriate FSH dose will be injected differently from one woman to another. Ovarian response to these drugs should be closely monitored by the medical team with repeated doses of estradiol in the blood and ultrasounds.
When multiple follicles with a diameter of 16 to 18 mm are developed in the surface of the ovaries, it sends an outbreak of ovulation with a hormone having the effects of LH (pituitary hormone that causes ovulation), c is the so-called human chorionic gonadotropin hormone HCG.
The oocyte collection
It is performed approximately 36 hours after the HCG injection, under general anesthesia. A short hospital stay of one day is required. The gynecologist visualized follicles that protrude from the surface of the ovary. Then, using a fine needle, it passes through the vaginal wall and draws one by one the contents of follicles (eggs surrounded by some cells bathed in follicular fluid). The syringes containing the follicular fluid are given in the laboratory. The biologist examines these liquids under binocular microscope, isolated cumulus cells-oocyte complexes (oocytes surrounded by follicular cells), transferred to a suitable medium and puts them in the incubator waiting for the time to put them in fertilization.
In vitro fertilization properly so called
On the day of oocyte retrieval, the spouse takes its semen by masturbation to the lab in a room fitted for this purpose. The sperm is processed to select the most motile sperm and the more fertilizing one. Then, oocytes and sperm are placed in a proper environment that best suits to their survival and placed in the incubator at 37 ° C. This is the step of in fertilization in vitro.
Within 18 to 24 hours, the biologist eliminates the follicular cells surrounding the oocyte and control the microscope if fertilization has occurred. The fertilized egg is then in the form of a cell containing two cores one from the father the other of maternal origin. This cell is called the zygote, the nuclei are called pronuclear or PN. After 48 hours of incubation the zygote develops into an embryo consists of several cells called blastomeric, the assembly being surrounded by a pellucid zone.
The transfer of embryos in the womb
It can take place at D2 (48 hours after oocyte retrieval), D3 (72 hours) or even D5 (see below the prolonged culture). That day, the biologist selects embryos to transfer. When there are surplus embryos of good quality, they will be frozen for later use.
The transfer is painless; it generally requires no anesthesia or hospitalization.
Embryos contained in a drop of a proper environment that is aspirated using a catheter (similar to that used for insemination). The latter is introduced through the cervical canal into the uterus, where the embryos are deposited.
A progesterone treatment is prescribed.
Fourteen days after the transfer, an assay of beta-HCG will be made to diagnose a possible pregnancy.