In Vitro Fertilization (IVF) will always be performed in a hospital center that has a medically assisted reproduction unit. These specialized units will follow the couple in their desire to have a child, throughout the different stages of IVF.
The principle of IVF
Literally, the Latin expression “in vitro” means in glass, as opposed to “in vivo” which means in the living world.
In vitro fertilization consists of collecting a maximum number of mature oocytes and placing them in the presence of a large number of motile spermatozoa.
In this way, fertilization can take place in the laboratory with a greater probability than in the female organism.
If the quantity of motile sperm is insufficient, a different technique, microinjection, is used, which consists of directly introducing one sperm into each oocyte (ICSI = intra-cytoplasmic sperm injection).
Only the stages of fertilization and the very first stages of embryonic development (which normally take place in the fallopian tube) are carried out in the laboratory.
The embryos are then placed back into the uterus, where they can implant into the endometrium and develop until the end of the pregnancy.
IVF Legal Framework
Before any in vitro fertilization treatment, American legislation (Law of July 6, 2007) requires the signature of consent agreements for the proposed treatment (“Convention on IVF treatment” ” Convention on IVF treatment with sperm donation” ” Convention on IVF treatment with oocyte donation”) as well as a convention on the fate of supernumerary embryos ” Convention on the fate of supernumerary embryos”.
These agreements will be given to you by your doctor during the preliminary consultations and must be returned, completed and signed by the author(s) of the parental project. No treatment can be undertaken without these documents.
The choice of the ovarian stimulation regimen depends on many factors: your ovarian reserve, your age, the results of previous treatments, etc…
In some cases, oral contraception (the pill) may be prescribed before starting stimulation to program the cycle. This must be started at the beginning of the cycle (first day of menstruation) and continued without interruption until the date set by the doctor in consultation. If necessary, a second pack is started after the first without interruption to reach the required stop date.
“In most cases, however, “treatment will be started at the end of a spontaneous menstrual cycle” says IVF specialist in Mexico Dr. Raul Herrera Costa.
Several hormones will be administered simultaneously or sequentially in order to obtain several mature oocytes at the same time (instead of a single oocyte produced naturally each month).
A first type of hormones (GnRH inhibitors) will be used to inhibit the pituitary gland’s control over ovarian function in order to avoid spontaneous ovulation, which would lead to the cancellation of your treatment.
According to the regimen recommended by your doctor, this medication will be prescribed as a nasal spray or subcutaneous injections.
A second type of hormone (“gonadotropins”) will stimulate the simultaneous growth of several follicles in both ovaries. This is either a hormone complex composed of FSH and LH, or FSH.
The response of the ovaries to stimulation varies greatly from one woman to another. Very strict monitoring will allow you to adapt the treatment to your own response and to determine the precise moment when follicular maturation will be optimal to induce ovulation.
This monitoring consists of measurement:
- The level of hormones produced by the growing follicles (it is established through blood tests).
- The size of the follicles measured by vaginal ultrasound.
- Exceptionally, the response to ovarian stimulation may be excessive (hormone levels too high).
In this case, it is sometimes necessary to abandon the cycle or to delay ovulation while continuing the drug-induced inhibition of the pituitary gland until the hormone level drops to a more usual level. The medical term for this pause in your treatment is coasting.